As a Subaru tech, I found this very informative! I wish they would make more of these, as the eCVT through gear action is much more reliable than the pull chain CVTs in all of our other vehicles. PHEV is a great transition to full EV adoption as it gradually increases the load on the power grid for charging. Thank you professor, I enjoyed the video and the cutaway transmission.
To help avoid the disaster of the total electric grid collapse if and when the incorrect politically mandates in the future hybrid vehicles are the intelliigent realistic choice.
O*U*T*S*T*A*N*D*I*N*G*! A model demonstration, clear, concise, accurate, logical, and on a personal note, I found it quite delightful! Thank you very much Professor Kelly for showing the rest of the world how it is done!
You're putting more effort in editing the videos and it really shows. I like that you've made it look a lot fancier yet not changed the base style, makes it feel much more personal and genuine. Keep it up.
I was weirdly STUCK to my TV screen watching this specific video... the rear drive clutch is a truly fascinating engineering design... using a low power /low torque electromagnet clutch to trigger a high-force mechanical "ball-ramp" actuator that utilizes the high-power system to actuate the "real" clutch-pack... so cool! Apparently as the clutch friction disc's wear and become thinner, the balls will travel farther up the ramp to compensate for the wear... nice. I design small electro-mechanical systems, I'll have to remember this trick!
Fascinating video. These Subaru hybrids seem to be incredibly rare, so even during my time working at a Japanese car specialist, I’ve never worked on one of these. I just assumed that, given Toyota’s substantial influence on Subaru and their recent parts/vehicle sharing, Subaru was using a hybrid system with a similar design to the THS. I did not expect it to be basically an exact clone, just repackaged for the unique drivetrain layout Subaru uses. I’m also surprised to learn that the older Subaru hybrid vehicles were parallel hybrids. I look forward to seeing a video on the older setup. Honestly, if I were in the market for a Crosstrek, I’d be much more interested in the PHEV version. The light-duty Subaru CVTs are trash, the power split CVTs like the THS uses are practically indestructible with basic maintenance. The AWD system looks to be very similar in theoretical operation as the system they’ve used in their automatics since the early 90s. The system has always been electronically activated, and they’ve always been FWD if the AWD actuation is off. They used to call it the transfer clutch. This one is different from at least the old 4 and 5 speed autos (and I assume the CVTs) in the sense that it is fully electromechanical. In the 4 and 5 speeds (and probably the CVT) it is electrohydraulic, using a solenoid to control fluid pressure to the transfer clutch (just like any other clutch pack in an automatic). Makes sense that they would make this an electromechanical system instead since this style of hybrid system does not necessarily require a high-pressure fluid pump like an automatic or CVT would.
Very impressive! Super job on that cutout of the case. I’d recommend auto journalists watch your channel. They will learn why this CVT feels so much better than the ‘older’ CVTs 😎
My wife and I each own one of these vehicles (2022 and 2023) and love them. There does seem to be something special about them and watching your video shows one more reason why. Thank you for the education! I’m always trying to learn more about this new world we all live in.
All these years later since I first started watching this channel for technical information and it's still masterclass stuff! Better than ever actually.
Thank you John Kelly for all that you have done through the years. I just noticed in the GM emerging issues that you have been a GM world-class technician for over 20 years. I want to thank you for sharing all your knowledge with us! I love learning about hybrid and electric vehicles so I am very thankful for your videos.
Amazing how rhe "NEW" is always just an inovation of old tech that transmission looks just like an old manual gear box with electric motors an amazing video thank you for your servive 👏👏👍
Hi, Professor John Kelly, I would like to salute you, your hard work and explaining style. Actually you teach like a respected primary school teacher which is amazing for me. I am a civil engineer but now I know many things about mechanical technology specially EVs and their transmission systems. Keep it up, be blessed with such teaching power. Thank you.
I purchased a 2013 Ford Cmax PRIOR to discovery of this channel. And I SOLD it based on the information from this channel. The car still operated ok at 138,000 miles, but based on this channel I felt either the CVT or the battery pack were on borrowed time. I didn’t like how violently the car shook when the gas engine started when cold. Even after a spark plug/coil pack change, it didn’t improve much(was still running original plugs/coil packs). I sleep much better now😁
Mr. Professor, the first time I saw you is that watched your prius hybrid structure explannation. It is quite impressive. I appreciate your expertise in THS technology.
This guy is absolutely awesome teaching... At beginning didn't want to watch the full but after the second minute I didn't want to stopped he made so interesting
You make incredible videos andI appreciate what you do. Every video is a masterclass. Thank you for what you do and I hope TH-cam is kind to you because you are giving away years and years of training and education with every video. Saint like automotive education charity you offer to the world.
I really like the transfer case solution! It’s like an electrical relay, it would take an enormous amount of energy to squeeze the clutch pack directly, instead this solution uses a small clutch that regulates the ramp system that uses the output torque from the transmission.
Thank you for the simplified explanation. Although it is complex, it differs from the previous Toyota hybrid system. However, re-explaining several times is easy. Thank you
Great video! Thank you so much for breaking all of this down in such detail! I own a 2023 Crosstrek PHEV and absolutely love it. Great to see what is going on inside.
@@WeberAuto My pleasure! I can drive all around Montreal on an 80-90% charge typically since there are a lot of lights and traffic. The regen braking and "B-Mode" down hills and coming to stops squeezes out a little more range each commute. I never use petrol in the city and the Atkinson' cycle boxer gets me between 6.5 and 7.5 L / 100km mileage on my weekly 400km roundtrip that I must do to and from Gatineau. This is quite impressive considering I always make this longer trip packed heavily (clothes, tools and camera gear) with both my bike and kayak racks on the roof. In other words, I am not driving long distance efficiently as I am adding considerable weight and significant drag. This route is also prone to very heavy winds and yet my mileage is still really good. This vehicle is truly a fantastic example of great AWD technology and it keeps me safe in all weather (heavy storms, snow and wind) and lets me go off road or bum about the city :) I am even trying to document my PHEV life a little bit for others who might want to take the leap into PHEV's or even full EV's: raven7818.zenfolio.com/blog It is not even close to how informative that your video was in just 40 minutes, but it is enjoyable to do when I get the time!
@@WeberAuto Really love this video and have watched it multiple times through! I have a question about the oil pump since I want to care for my PHEV in the best way possible. I live in Montreal and it can get quite cold (-25 C at times) and when I do things like hit the highway or turn on the defrosters the Boxer will kick in when I am in EV Mode. My question is this: Does the Oil pump pre-prep the boxer engine at all when I am driving in EV mode only? I ask this since I find it a bit harsh that the Boxer will kick in "cold" while driving in EV mode under these specific conditions. When this happens, I force it into charge mode until the motor warms sufficiently and only after that drop it back into EV only or Save Mode. If the oil pump is circulating oil through the actual motor, even when only under EV drive then that would explain why the Subaru can support starting the engine mid-drive. Thanks for your time and great explanations!
Hey Prof, thanks for yet another great disassembly video. I hope you enjoy making them even half as much as I enjoy watching them. BTW, I like the new graphics! 🖖
Hi Professor, just want to re-iterate most other comments regarding your excellent explanation and presentation on this transmission. I'm an ex-mechanic and remember pulling apart manual 3 speed transmissions which only had 5 or 6 gears in total and were so simple. Hats off to the mechanical and electrical engineering team of these types of transmissions that are able to get complex systems seemingly working in harmony. Thanks again and really enjoy the content you and your team create !!!!
John - I was one of the doubters about the planetary gear tooth counts (at timestamp 14:00). After some research, I found the answer. The "equivalent diameters" of the gears must indeed follow the ring = sun + 2 x planet formula, but there's more to it. The power splitter uses "positive profile offset" gears with a somewhat triangular tooth shape, which gives stronger teeth. It also gives a different equivalent diameter than you'd expect from the tooth count and tooth pitch. The sun and planet gears have smaller-than-expected equivalent diameters, and the ring has a larger equivalent diameter. With that adjustment, 30 teeth + 2 x 25 teeth really does add up to 78 teeth, not 80. Thank you again for the video you posted a couple of years ago demonstrating the tooth counts on the Rav4, which launched me on that investigation. - Joe C.
The working pitch diameters must follow the ring = sun +2 x planet formula (working pitch diameters as inputs). The tooth profile shift (x) is used to adjust/correct center distance when this geometric constraint equation of center distances can't be met when inputting number of teeth (dividing the two sides of equation by the module). We see it when inputing the formula with the reference pitch diameters (single gears, dref=m.z), it doesn't fit. In this Subaru planetary gear, the working pitch diameter must compensate the lack of 2 teeth which yields in 2.m/2 less center distance of the ring gear. So the sum of profile shifts applied to the gear set must be equal to -2 (xs+xp+xr=-2) in order to correct this smaller center distance. The looman's assembly rule must be met (zr+zs)/np = integer in order to provide equal spacing of the planetaries. The following article explains it (concept B and C) www.geartechnology.com/ext/resources/issues/0913x/light-weight-planetary.pdf
25:50 I do believe Toyota allows MG1 combine power with MG2 for the RAV4 Prime, as seen for the P810 transmission power output is much higher in PHEV than in HV only for the Highlander hybrid or the new Sienna, this also seems to apply for Lexus NX450h+, RX450h+ and Toyota Harrier PHEV just released in Japan
Yes, in general the current generation of the Prime versions - but only the Prime versions - of Toyota transverse hybrid transaxles have an overrunning clutch that allows MG1 to drive in EV mode.
Thank you sooo much for these extremely detailed explanation of the hybrid. I checked so many videos, articles and even the manual and there were all vague. I actually have a 2014 Crosstrek since the beginning but I want to do something fun. After learning about how the hybrid's electric motors help with acceleration and torque, I thought about getting another one just for fun to mod it and have something a bit unique. Although neat when I'm driving casually, I don't want it for MPG again, I just like the idea that having more responsive torque and acceleration before the gas engine gets into peak power. There's now a turbo kit available for the Crosstrek and even bolt on superchargers. I doubt the CVT can handle too much power but I just like the fun idea of making it all more peppy. Add in a cold intake, different exhaust and an ECU tune, I think it would be a fun rally-lite car and off-roader. I'm just so fascinated about the electric motor part. I actually like my 2014's CVT in daily driving (especially since I live in Chicago, and I can be stuck in stop & go traffic for an hour or more without even leaving the city). I know this all sounds super dumb and crazy, since it was never meant to be a "sporty" car. But I'm thinking about buying a used 2019 Crosstrek Hybrid to do the turbo kit mod on it and everything else I mentioned. Do you think I'd need to find a way to cool the batteries even better? Or have major issues? With some diagnostic tools or access, could I put the car into a "performance mode" where it uses the electric motor even more so for initial acceleration and torque?
What a great way to learn about new mechanical methods to transmit a power band... I'm a mechanical engineering student from frankfurt germany and I feel privileged to have such great professional source of information just one click away. I hope I can take a visite some day.
Excellent. I couldn't imagine how a planetary gear system could be infinitely variable, but you cleared that right up, as well as explaining why the system has two electric motor/generators, and how it integrates the other standard transmission features, as well as the AWD rear wheel link-up. The only part I don't recall seeing was how they deal with reverse. Is that handled electric only? In addition to eliminating the CVT drive belt, which is problematic with some uses and intolerant of abusive driving, this system also eliminates the traditional hydraulic control systems, valve bodies, solenoids and clutch packs of conventional automatics, as well as a torque converter. It seems like an effective marriage of the direct power flow of a manual transmission with the convenience of a CVT automatic.
That would normally be called a "transfer case"... but yes, it's the same thing as this, without the front differential in the same case, with a different rear drive coupling, and with a two-speed planetary gear transmission instead of the fixed-ratio planetary reduction gear for MG2.
@@WeberAuto What do you think: why Lexus does not allow ICE (Engine) and MG2 motor work simultaneously to increase power and torque? Engine is 398hp/530nm and MG2 is 165Kw (220hp)/300nm torque. This could be 618hp/830nm torque which would make this Lexus LS600h amazing to drive. When LS600h accelerating in wide open throttle applying all engine's power to the wheels, the MG2 only freely rotates never adding any power? Why? If we manually control the MG2, can it add up the power?
@@WeberAuto Maybe MG1 moving at different speeds to emulate gears takes some of engine torque and affects it's performance while at the same time working as a generator for the MG2. If during WOT the engine and MG2 works together but MG1 slows everything down for "gearing work", it explains why Lexus rates LS600h only 420hp and almost untouched engine torque numbers. Or maybe I am saying the utter nonsense here. Anyway it is hard to explain why LS600h is only 420hp if it has a 165kw MG2.
I have the 2020 Crosstrek PHEV. It has been a great vehicle. I have over 73k on it and it has only had oil changes, filters and tires. I average about 60 mpg over a tank of gas and sometimes go 715 miles between fill ups with very low electric charging cost. I use 120v at home and slightly faster charging at charging stations.
I can't find actual specs anywhere, could you answer my questions? What is the battery only range, and what is the actual MPG after the battery is depleted? You can easily figure this out by starting a trip odometer after the battery is dead. I'm wondering because I have a Chevy Volt and it is far from the advertised specs, because of course it depends on how long your trips are and how often you charge. You can't give a PHEV a generic MPG rating like that.
@@TheYonderGod The advertised EV range is 17 miles, that’s what it will show available unless you turn on the heat or a/c, in which case it will show 15 miles range. You drive a mile before the capacity drops from 17 to 16 so in my book that equates to 18 miles. If I ran by battery down and just continued under gas/hybrid mode the advertised mpg is 30-35mpg. That is what I usually get when we take the car on a trip of several hundred miles. I am always looking for a free place to charge along my way even though this car has a slow charging speed. It takes about 2hrs 10min at a level 1 charging stating for a full charge; the last couple miles take the longest to top off. I charge whenever I’m at home so over a tank of gas my average recorded mpg tends to be anywhere from 50-70mpg. It varies greatly depending on daily miles and route.
@@rkymtnrsx thanks, that's the info I was looking for. Crazy that nobody has improved on the technology from that came out in the Volt 10 years ago, other than the small upgrade on the gen2 in 2016.
@@TheYonderGod 😊👍 When I test drove used Volts (great car BTW!) one car had lifetime average of 39mpg, and the other's lifetime was 260mpg. Guess which one was a fleet car for an insurance company? The other was privately owned & garaged nightly. I ended up with an i3 REx. 24k miles on 25 gallons last year. 1 speed series hybrid. PHEVs & range extenders are great.
Thank you very much for your nice and fàntastic video . I wish you a very Happy New Year , 2023 ! With lots of love and regards , Jayantàda , 31/12/2022
The mechanical AWD is fundamentally less capable of suitable control than the electric rear drive. The only advantage is that Toyota only equips the rear drive with sufficient cooling for limited operation, so the power sent to the rear and the time it is used are limited. Both systems must minimize rear drive operation to improve efficiency, so they're both just front wheel drive until needed.
The solenoid and ball ramp rear drive clutch is a very common design. It can be found in the transaxle (as here) or in front of the rear final drive (differential) in various brands of vehicles which use variable clutch actuation to drive the rear axle. So this nice explanation of that clutch system also applies to many other vehicles.
I wonder why Subaru would not flip their default configuration and makes rear wheel drive by default and use the ball ramp to send torque to the front axle? It would certainly give the car a more dynamic driving experience. It's not like it has some packaging restrictions since pretty much all the hardware is already their in their symmetric AWD layout, except they have to provide a much beefier drive shaft to handle the constant torque to the back, and prob. reinforce the rear suspension a little. But to me, that would be a relatively small design change to be able to place their cars in a completely different market segment.
@@brucechan9140 These cars are very front-heavy, so primarily RWD would not be desirable. The rear final drive might need to be stronger, but the drive torque distribution would matter very little to suspension.
@@brianb-p6586 I agree with you completely on the fact that subaru is inherently front heavy, the engine is actually mounted mostly in front of the front drive shafts. But I dont see why weight distribution has anything to do with driving torque send to the back. Afterall, there are plenty of pickup trucks with empty beds rolling down the roads everyday. And if I am not mistaken, audi's longitudinal quattro layout with torsen center diff is rear biased. I don't see why subaru can't do it.
Awesome. Very similar to the Lexus GS450h hybrid gearbox, but instead of a neat spragge clutch to drive the oil pump from two sources it uses an electric oil pump for electric only mode.
I wish we could find one of these in our area. We love our Impreza and have previous experience with plug-in hybrids and it'd be great to get an awesome combo of both of those.
What a fascinating transmission. While the electronically variable ratio is the star of the show (I believe the Ford Maverick hybrid is similar), it is the rear drive clutches that really caught me by surprise. Clearly the electromagnetic clutch couldn't carry a meaningful load, but using that clutch to make the ball ramp clamp the 'real' clutch is so mechanically simple that it is genius. The pump drive is also quite clever. That's an expensive transmission but should last almost forever. Even the clutches should see little wear since they won't really see meaningful slip. It looks like they could be replaced without splitting the case. Thank you for another great video!
Another amazing video John! We recently bought a 2022 KIA Sorento PHEV. I would like to see a video on the transmission. I have driven the 2017 Chevy Volt PHEV, and A 2020 Rav4 Hybrid, but the 2022 KIA PHEV Sorento is different. I notice that in EV Only mode it still shifts the 5 speed Automatic transmission, Kinda neat as this gives plenty of torque in 1st gear and also eases the RPM at highway speeds. MFG states 32 miles on EV, but in Phoenix with the A/C on driving the freeways I can go 37 miles on EV only.
@weberauto Love your channel, thanks for everything you do. Im a hybrid technichian, I work at mobilityworks on wheelchair accessible vehicles. I work on a lot of Sienna hybrids, used to work on a lot of Honda IMA and own a Mitsubishi Outlander PHEV. Any plans to dive into Mitsubishi products? I think you would find Mitsubishi phev transmission interesting, in my opinion an ecvt is a better design and more efficient but its not a bad transmission. It's a gkn multimode etransaxle if your interested in learning more. You're the best John!
Yes be great to see John do his deep dive into the Mitsi PHEV and it's VtoH (vehicle to home ) capabilities . I'm so impressed with my 2014 Mitsi PHEV (270K miles ,its still on the original 12KW battery) it's never let us down towing a heavy caravan, lot of the time of road , the Mitsi 4wd electric drivetrain is bomb proof , it has a 80 kw engine driven generator similar to Toyota RAV4 PHEV. But we found when stationery in charge mode powering our off grid caravan via the 12 kw battery, it's more fuel efficient and quieter than our 10 hp honda generator in our experience. A Bonus in charge Mode is we can heat and cool the caravan via a fan assisted ducting from the standard electric Mitsi PHEV AC/Heating So impressed I've bought a 3rd Mitsi PHEV now 🙈 Thanks John for your great channel 👍
The Mitsubishi Outlander PHEV transaxle is functionally identical to the Honda i-MMD (or "E-Drive") that Dr. Kelly did about a year ago; however, it is constructed differently.
@@brianb-p6586 thanks for that, just enjoyed watching that again 👍.... but the main game changer with the original 2014 Mitsi PHEV is it's ability to charge V2H or V2G ( vehicle to Home/Grid) this is the main feature ( V2H) the 2019- 21 Honda still does NOT have V2H from the ICE ( Internal Combustion Engine) that's why it would enjoy the brilliant Dr Kelly doing his deep dive series on the Mitsi PHEV standard Charge Mode & V2H capabilities 😎👍
@24:54, regarding using both MG1 and MG2: correct, this system cannot use both MG1 and MG2 as motors to drive the vehicle without the engine running, because it is lacking the one-way clutch (as used in a Prius Prime for this purpose) which would be required to avoid spinning the engine. It can use both MG1 and MG2 in a power-split mode, but in that case MG2 is generating, MG1 is motoring, all of the power to the wheels is going through the planetary gearset, and electrical power is recirculating from transaxle output to input to make this happen - it is an undesirable but possible mode of any input power-split transmission which occurs only when the relative engine and output speeds require it.
Again and again good cognitive lesson. Thank you professor John Kelly -you are my distance learning teacher. if possible make video abot Volksvagen ID4 and ID six please . Watching all your videos-Take care dear mr. Kelly .
This is exactly what I've been looking for! I've always been a fan of the 2019 plug-in Crosstrek & thought it was a fantastic collaboration of parts bins from the best of the two companies. What I'm so immensely frustrated is why Subaru did NOT apply this to either a Forester, Legacy, or Ascent platform. You would have significantly more room to pack the lithium battery, achieve better EV-only range, and still retain the mechanical AWD system. IF there was a PHEV Forester, it would really have been a killer to the Hyundai, Volvo, and BMW offerings - with a MUCH more capable AWD system for all road conditions. That, and it would've been a GREAT precursor for the RAV4 Prime instead of Toyota stealing the thunder with their late-released RAV4 Prime.
As a Subaru tech, I found this very informative! I wish they would make more of these, as the eCVT through gear action is much more reliable than the pull chain CVTs in all of our other vehicles. PHEV is a great transition to full EV adoption as it gradually increases the load on the power grid for charging. Thank you professor, I enjoyed the video and the cutaway transmission.
totally agree with you
To help avoid the disaster of the total electric grid collapse if and when the incorrect politically mandates in the future hybrid vehicles are the intelliigent realistic choice.
I love your explainings, good to understand. Thanks Professor Kelly
This is a really neat application of the e-CVT. The cutaway you and Nash put together is fantastic. Thank you!
Thank you, I will tell Nash.
Every body realize that Synergy drive and plug-in from Toyota Prius is a genius design 😎
Thanks John.
Thank you!
O*U*T*S*T*A*N*D*I*N*G*! A model demonstration, clear, concise, accurate, logical, and on a personal note, I found it quite delightful! Thank you very much Professor Kelly for showing the rest of the world how it is done!
Thank you so much!
👏🏽👏🏽👏🏽👏🏽👏🏽👏🏽
You're putting more effort in editing the videos and it really shows. I like that you've made it look a lot fancier yet not changed the base style, makes it feel much more personal and genuine. Keep it up.
I appreciate that!
I was weirdly STUCK to my TV screen watching this specific video... the rear drive clutch is a truly fascinating engineering design... using a low power /low torque electromagnet clutch to trigger a high-force mechanical "ball-ramp" actuator that utilizes the high-power system to actuate the "real" clutch-pack... so cool!
Apparently as the clutch friction disc's wear and become thinner, the balls will travel farther up the ramp to compensate for the wear... nice.
I design small electro-mechanical systems, I'll have to remember this trick!
Fascinating video. These Subaru hybrids seem to be incredibly rare, so even during my time working at a Japanese car specialist, I’ve never worked on one of these. I just assumed that, given Toyota’s substantial influence on Subaru and their recent parts/vehicle sharing, Subaru was using a hybrid system with a similar design to the THS. I did not expect it to be basically an exact clone, just repackaged for the unique drivetrain layout Subaru uses. I’m also surprised to learn that the older Subaru hybrid vehicles were parallel hybrids. I look forward to seeing a video on the older setup.
Honestly, if I were in the market for a Crosstrek, I’d be much more interested in the PHEV version. The light-duty Subaru CVTs are trash, the power split CVTs like the THS uses are practically indestructible with basic maintenance.
The AWD system looks to be very similar in theoretical operation as the system they’ve used in their automatics since the early 90s. The system has always been electronically activated, and they’ve always been FWD if the AWD actuation is off. They used to call it the transfer clutch. This one is different from at least the old 4 and 5 speed autos (and I assume the CVTs) in the sense that it is fully electromechanical. In the 4 and 5 speeds (and probably the CVT) it is electrohydraulic, using a solenoid to control fluid pressure to the transfer clutch (just like any other clutch pack in an automatic). Makes sense that they would make this an electromechanical system instead since this style of hybrid system does not necessarily require a high-pressure fluid pump like an automatic or CVT would.
just curious what did you study since you worked as a Japanese car specialist?
Thank you, and thanks for the information.
Very impressive!
Super job on that cutout of the case.
I’d recommend auto journalists watch your channel. They will learn why this CVT feels so much better than the ‘older’ CVTs 😎
I have recommended this channel several times to specific journalists after reading errors in their work.
Thank you very much!
@@Miata822 right on, Bill 👏🏼
Professor Kelly is the best, without a doubt.
Just look at all the P-Touch labelling! Details, details…
Good luck. Motoring "journalists" these days don't seem very interested in understanding how cars work beyond the interior of the cabin 😒
@@WeberAuto I have recommended this video and sent links to three automotive technicians that I know.
My wife and I each own one of these vehicles (2022 and 2023) and love them. There does seem to be something special about them and watching your video shows one more reason why. Thank you for the education! I’m always trying to learn more about this new world we all live in.
All these years later since I first started watching this channel for technical information and it's still masterclass stuff! Better than ever actually.
Thank you very much Rick!
Thank you John Kelly for all that you have done through the years. I just noticed in the GM emerging issues that you have been a GM world-class technician for over 20 years. I want to thank you for sharing all your knowledge with us! I love learning about hybrid and electric vehicles so I am very thankful for your videos.
Thank you Aaron!
Amazing how rhe "NEW" is always just an inovation of old tech that transmission looks just like an old manual gear box with electric motors an amazing video thank you for your servive 👏👏👍
Dr Kelly -- You are a truly talented instructor! Clear, complete, and concise!
We all appreciate what youre doing. Well explained as always. Thank you for your work.
Thank you very much!
Hi, Professor John Kelly,
I would like to salute you, your hard work and explaining style. Actually you teach like a respected primary school teacher which is amazing for me. I am a civil engineer but now I know many things about mechanical technology specially EVs and their transmission systems. Keep it up, be blessed with such teaching power. Thank you.
I purchased a 2013 Ford Cmax PRIOR to discovery of this channel. And I SOLD it based on the information from this channel. The car still operated ok at 138,000 miles, but based on this channel I felt either the CVT or the battery pack were on borrowed time. I didn’t like how violently the car shook when the gas engine started when cold. Even after a spark plug/coil pack change, it didn’t improve much(was still running original plugs/coil packs). I sleep much better now😁
Mr. Professor, the first time I saw you is that watched your prius hybrid structure explannation. It is quite impressive. I appreciate your expertise in THS technology.
The CVT distinctions, ball ramp demonstration, and cutaway were most helpful. Thanks!
What an impressive video, I was impressed about this technology, now I am in love of it. This system is so simple yet so smart made.
Thanks
Thank you @bosmanx!
Danke!
You are welcome
This guy is absolutely awesome teaching... At beginning didn't want to watch the full but after the second minute I didn't want to stopped he made so interesting
You deserve to be a professor, but more than that because of your simplified explanation and your great knowledge
This was an incredible demonstration. Thank you!!!
Big Thank You prof. Kelly (and of course assistant Nash), this is the best explanation of Subaru PHEW AWD drivetrain I ever seen.
You make incredible videos andI appreciate what you do. Every video is a masterclass. Thank you for what you do and I hope TH-cam is kind to you because you are giving away years and years of training and education with every video. Saint like automotive education charity you offer to the world.
Thank you so much!
such a great channel! Thanks Professor for all those great masterclasses over the years.
Great video professor Kelly 👍🏼 Really enjoy watching these and still miss being in class!
Thank you!
This channel is such a treasure
I really like the transfer case solution! It’s like an electrical relay, it would take an enormous amount of energy to squeeze the clutch pack directly, instead this solution uses a small clutch that regulates the ramp system that uses the output torque from the transmission.
Thanks for your feedback!
Yes, it is servo actuation approach.
This is incredible. I never liked the regular Subaru cvt, and the reliability of the eCVT makes this car on a different level.
When Professor John talks, I learn.
Thanks man.
You are welcome!
Thank you for the simplified explanation. Although it is complex, it differs from the previous Toyota hybrid system. However, re-explaining several times is easy. Thank you
Absolutely great education! Still wainting for your next video!
Great video! Thank you so much for breaking all of this down in such detail! I own a 2023 Crosstrek PHEV and absolutely love it. Great to see what is going on inside.
Thank you!
@@WeberAuto My pleasure! I can drive all around Montreal on an 80-90% charge typically since there are a lot of lights and traffic. The regen braking and "B-Mode" down hills and coming to stops squeezes out a little more range each commute. I never use petrol in the city and the Atkinson' cycle boxer gets me between 6.5 and 7.5 L / 100km mileage on my weekly 400km roundtrip that I must do to and from Gatineau. This is quite impressive considering I always make this longer trip packed heavily (clothes, tools and camera gear) with both my bike and kayak racks on the roof. In other words, I am not driving long distance efficiently as I am adding considerable weight and significant drag. This route is also prone to very heavy winds and yet my mileage is still really good. This vehicle is truly a fantastic example of great AWD technology and it keeps me safe in all weather (heavy storms, snow and wind) and lets me go off road or bum about the city :) I am even trying to document my PHEV life a little bit for others who might want to take the leap into PHEV's or even full EV's: raven7818.zenfolio.com/blog It is not even close to how informative that your video was in just 40 minutes, but it is enjoyable to do when I get the time!
@@WeberAuto Really love this video and have watched it multiple times through! I have a question about the oil pump since I want to care for my PHEV in the best way possible. I live in Montreal and it can get quite cold (-25 C at times) and when I do things like hit the highway or turn on the defrosters the Boxer will kick in when I am in EV Mode. My question is this: Does the Oil pump pre-prep the boxer engine at all when I am driving in EV mode only? I ask this since I find it a bit harsh that the Boxer will kick in "cold" while driving in EV mode under these specific conditions. When this happens, I force it into charge mode until the motor warms sufficiently and only after that drop it back into EV only or Save Mode. If the oil pump is circulating oil through the actual motor, even when only under EV drive then that would explain why the Subaru can support starting the engine mid-drive. Thanks for your time and great explanations!
Hey Prof, thanks for yet another great disassembly video. I hope you enjoy making them even half as much as I enjoy watching them. BTW, I like the new graphics! 🖖
Thank you very much! It is a lot of fun for me to explore these. Thanks for the feedback on the graphics too!
Thank you for your distinct videos explaining driving technology meticulously. Looking forward to more videos.
Love how you can do this without getting your hands dirty!
New and cleaned parts
Hi Professor, just want to re-iterate most other comments regarding your excellent explanation and presentation on this transmission. I'm an ex-mechanic and remember pulling
apart manual 3 speed transmissions which only had 5 or 6 gears in total and were so simple. Hats off to the mechanical and electrical engineering team of these types of
transmissions that are able to get complex systems seemingly working in harmony. Thanks again and really enjoy the content you and your team create !!!!
Thanks for that!
I 'm watching you video from Ukraine. Very cool. I'm bad undenstanding, but I'm learning English.
Thank you!
my favorite professor. Thank You for the video!!!
Exceptional demonstration! Thank you for your enthusiasm and willingness to share your talents. 👍
Your shares are very valuable. I congratulate you for your hard work, professor.
John - I was one of the doubters about the planetary gear tooth counts (at timestamp 14:00). After some research, I found the answer. The "equivalent diameters" of the gears must indeed follow the ring = sun + 2 x planet formula, but there's more to it. The power splitter uses "positive profile offset" gears with a somewhat triangular tooth shape, which gives stronger teeth. It also gives a different equivalent diameter than you'd expect from the tooth count and tooth pitch. The sun and planet gears have smaller-than-expected equivalent diameters, and the ring has a larger equivalent diameter. With that adjustment, 30 teeth + 2 x 25 teeth really does add up to 78 teeth, not 80.
Thank you again for the video you posted a couple of years ago demonstrating the tooth counts on the Rav4, which launched me on that investigation. - Joe C.
Great information. Thank you
The working pitch diameters must follow the ring = sun +2 x planet formula (working pitch diameters as inputs). The tooth profile shift (x) is used to adjust/correct center distance when this geometric constraint equation of center distances can't be met when inputting number of teeth (dividing the two sides of equation by the module). We see it when inputing the formula with the reference pitch diameters (single gears, dref=m.z), it doesn't fit. In this Subaru planetary gear, the working pitch diameter must compensate the lack of 2 teeth which yields in 2.m/2 less center distance of the ring gear. So the sum of profile shifts applied to the gear set must be equal to -2 (xs+xp+xr=-2) in order to correct this smaller center distance. The looman's assembly rule must be met (zr+zs)/np = integer in order to provide equal spacing of the planetaries.
The following article explains it (concept B and C) www.geartechnology.com/ext/resources/issues/0913x/light-weight-planetary.pdf
@@saintclairtrisotto9357 Excellent information, thank you!
Very impressive presentation. You have allayed all me fears about going this way.
25:50 I do believe Toyota allows MG1 combine power with MG2 for the RAV4 Prime, as seen for the P810 transmission power output is much higher in PHEV than in HV only for the Highlander hybrid or the new Sienna, this also seems to apply for Lexus NX450h+, RX450h+ and Toyota Harrier PHEV just released in Japan
Thanks for the information
Yes, in general the current generation of the Prime versions - but only the Prime versions - of Toyota transverse hybrid transaxles have an overrunning clutch that allows MG1 to drive in EV mode.
Thank you sooo much for these extremely detailed explanation of the hybrid. I checked so many videos, articles and even the manual and there were all vague. I actually have a 2014 Crosstrek since the beginning but I want to do something fun. After learning about how the hybrid's electric motors help with acceleration and torque, I thought about getting another one just for fun to mod it and have something a bit unique. Although neat when I'm driving casually, I don't want it for MPG again, I just like the idea that having more responsive torque and acceleration before the gas engine gets into peak power. There's now a turbo kit available for the Crosstrek and even bolt on superchargers. I doubt the CVT can handle too much power but I just like the fun idea of making it all more peppy. Add in a cold intake, different exhaust and an ECU tune, I think it would be a fun rally-lite car and off-roader. I'm just so fascinated about the electric motor part. I actually like my 2014's CVT in daily driving (especially since I live in Chicago, and I can be stuck in stop & go traffic for an hour or more without even leaving the city). I know this all sounds super dumb and crazy, since it was never meant to be a "sporty" car. But I'm thinking about buying a used 2019 Crosstrek Hybrid to do the turbo kit mod on it and everything else I mentioned. Do you think I'd need to find a way to cool the batteries even better? Or have major issues? With some diagnostic tools or access, could I put the car into a "performance mode" where it uses the electric motor even more so for initial acceleration and torque?
@WeberAuto I just like cars. I have not school on mechanics. But You are a wanderfull Teacher. Thank You
What a great way to learn about new mechanical methods to transmit a power band... I'm a mechanical engineering student from frankfurt germany and I feel privileged to have such great professional source of information just one click away. I hope I can take a visite some day.
Not all CVTs are the same. Great to know the eCVT from the Prius is on some of the hybrid Subarus as well. Great for parts sourcing
I doubt that the parts interchange.
Thank you very much. Very much informative, explanatory, easy to understand.
Incredible video, watched it twice. Thank you
They put a Subaru body on a Toyota. Real good Subaru way to show how smart your engineers really are!
It's not that at all. The Toyota AWD Hybrid's rear axle is only driven electrically. No driveshaft.
This was a great video. I never knew that Toyota owned part of Subaru.
I also never knew/seen an electric (or magnetic) clutch.
Great Job!
Thank you ! You do such a good job explaining how things work, always love your videos.
Amazing video save explain. And genius design of the cvt system that avoids all the reliability problems with few belt version
Thank you, Professor Kelly, you make it interesting and easy to understand.
What a cool and informational video :) Really awesome!
I love your very instructive videos, and can hardly wait until you get your hands on the 2023 Prius and Prius Prime! ;)
Excellent. I couldn't imagine how a planetary gear system could be infinitely variable, but you cleared that right up, as well as explaining why the system has two electric motor/generators, and how it integrates the other standard transmission features, as well as the AWD rear wheel link-up. The only part I don't recall seeing was how they deal with reverse. Is that handled electric only? In addition to eliminating the CVT drive belt, which is problematic with some uses and intolerant of abusive driving, this system also eliminates the traditional hydraulic control systems, valve bodies, solenoids and clutch packs of conventional automatics, as well as a torque converter. It seems like an effective marriage of the direct power flow of a manual transmission with the convenience of a CVT automatic.
Man your shop assistant is a lucky
Thank you!
LS600H transmission is also mechanical AWD but uses a GS450H trans as a base(with a added splitcase)
Very interesting to see the differences,
Thank you. I have one of those here and I hope to shoot a video on it someday.
That would normally be called a "transfer case"... but yes, it's the same thing as this, without the front differential in the same case, with a different rear drive coupling, and with a two-speed planetary gear transmission instead of the fixed-ratio planetary reduction gear for MG2.
@@brianb-p6586 yes also the LS600H T-case torque splits F40%/R60% which is the same as a bunch of Subaru Sti boxes does.
@@WeberAuto What do you think: why Lexus does not allow ICE (Engine) and MG2 motor work simultaneously to increase power and torque? Engine is 398hp/530nm and MG2 is 165Kw (220hp)/300nm torque. This could be 618hp/830nm torque which would make this Lexus LS600h amazing to drive. When LS600h accelerating in wide open throttle applying all engine's power to the wheels, the MG2 only freely rotates never adding any power? Why? If we manually control the MG2, can it add up the power?
@@WeberAuto Maybe MG1 moving at different speeds to emulate gears takes some of engine torque and affects it's performance while at the same time working as a generator for the MG2. If during WOT the engine and MG2 works together but MG1 slows everything down for "gearing work", it explains why Lexus rates LS600h only 420hp and almost untouched engine torque numbers. Or maybe I am saying the utter nonsense here. Anyway it is hard to explain why LS600h is only 420hp if it has a 165kw MG2.
Awsome Introduction to the ? electrtic tr580 , Very Well Done Sir
Excellent video Professor Kelly!
Great explanation, you seem to be a really good professor, really nice video!
Donated 50 € for your superb videos enlighten us with engineering insights! Best wishes from Germany! 🇩🇪❤️🇺🇲
Thank you very much!
Thanks a lot for your work. Very interesting and professionally presented content.
Thank you Prof. Kelly again
Really find your videos interesting. Thanks a lot.
amazing video with so much details. Thanks
this channel is gold ... top notch explanation been watching you for years ...
Thank you very much
Such a great Instructor
Great to see you, John!
I was literally just watching your Honda E-CVT video (again) and this Subaru video appeared 👍🏼
Awesome timing, thanks.
Cool, thanks!
I have the 2020 Crosstrek PHEV. It has been a great vehicle. I have over 73k on it and it has only had oil changes, filters and tires. I average about 60 mpg over a tank of gas and sometimes go 715 miles between fill ups with very low electric charging cost. I use 120v at home and slightly faster charging at charging stations.
Thanks for sharing
I can't find actual specs anywhere, could you answer my questions?
What is the battery only range, and what is the actual MPG after the battery is depleted? You can easily figure this out by starting a trip odometer after the battery is dead.
I'm wondering because I have a Chevy Volt and it is far from the advertised specs, because of course it depends on how long your trips are and how often you charge. You can't give a PHEV a generic MPG rating like that.
@@TheYonderGod The advertised EV range is 17 miles, that’s what it will show available unless you turn on the heat or a/c, in which case it will show 15 miles range. You drive a mile before the capacity drops from 17 to 16 so in my book that equates to 18 miles.
If I ran by battery down and just continued under gas/hybrid mode the advertised mpg is 30-35mpg. That is what I usually get when we take the car on a trip of several hundred miles. I am always looking for a free place to charge along my way even though this car has a slow charging speed. It takes about 2hrs 10min at a level 1 charging stating for a full charge; the last couple miles take the longest to top off. I charge whenever I’m at home so over a tank of gas my average recorded mpg tends to be anywhere from 50-70mpg. It varies greatly depending on daily miles and route.
@@rkymtnrsx thanks, that's the info I was looking for. Crazy that nobody has improved on the technology from that came out in the Volt 10 years ago, other than the small upgrade on the gen2 in 2016.
@@TheYonderGod
😊👍 When I test drove used Volts (great car BTW!) one car had lifetime average of 39mpg, and the other's lifetime was 260mpg.
Guess which one was a fleet car for an insurance company?
The other was privately owned & garaged nightly.
I ended up with an i3 REx.
24k miles on 25 gallons last year.
1 speed series hybrid.
PHEVs & range extenders are great.
Thank you very much for your nice and fàntastic video .
I wish you a very Happy New Year , 2023 !
With lots of love and regards ,
Jayantàda ,
31/12/2022
Awesome video and explanation! Thank you.
This video makes me want to get into drivetrain engineering
Thank you Mr. Kelly
Wonderful, interesting video as always. Still waiting for the day I will see the Lexus IS300h transmission video :)))))
thank you! phenomenal video. I wanted a rav4 hybrid but now id rather have the mechanical awd!
Cross-trek ECVT is marvelous, RAV4 probably lot easier to find, and more parts will be available in future
Thank you!
The mechanical AWD is fundamentally less capable of suitable control than the electric rear drive. The only advantage is that Toyota only equips the rear drive with sufficient cooling for limited operation, so the power sent to the rear and the time it is used are limited.
Both systems must minimize rear drive operation to improve efficiency, so they're both just front wheel drive until needed.
RAV4 has better system than this. It has lower losses in the drive line = better fuel efficiency. Offroad performance should be almost similar.
An inline Toyota 4 cylinder is much less prone to cylinder head failure than a Subaru boxer engine.
The solenoid and ball ramp rear drive clutch is a very common design. It can be found in the transaxle (as here) or in front of the rear final drive (differential) in various brands of vehicles which use variable clutch actuation to drive the rear axle. So this nice explanation of that clutch system also applies to many other vehicles.
It was news to me. Very clever design. I love mechanical simplicity.
Thank you, yes, I have seen it in AWD truck transfer cases too.
I wonder why Subaru would not flip their default configuration and makes rear wheel drive by default and use the ball ramp to send torque to the front axle? It would certainly give the car a more dynamic driving experience. It's not like it has some packaging restrictions since pretty much all the hardware is already their in their symmetric AWD layout, except they have to provide a much beefier drive shaft to handle the constant torque to the back, and prob. reinforce the rear suspension a little. But to me, that would be a relatively small design change to be able to place their cars in a completely different market segment.
@@brucechan9140 These cars are very front-heavy, so primarily RWD would not be desirable. The rear final drive might need to be stronger, but the drive torque distribution would matter very little to suspension.
@@brianb-p6586 I agree with you completely on the fact that subaru is inherently front heavy, the engine is actually mounted mostly in front of the front drive shafts. But I dont see why weight distribution has anything to do with driving torque send to the back. Afterall, there are plenty of pickup trucks with empty beds rolling down the roads everyday. And if I am not mistaken, audi's longitudinal quattro layout with torsen center diff is rear biased. I don't see why subaru can't do it.
Awesome. Very similar to the Lexus GS450h hybrid gearbox, but instead of a neat spragge clutch to drive the oil pump from two sources it uses an electric oil pump for electric only mode.
It's quite an impressive configuration. More than the regular toyota one
I wish we could find one of these in our area. We love our Impreza and have previous experience with plug-in hybrids and it'd be great to get an awesome combo of both of those.
What a fascinating transmission. While the electronically variable ratio is the star of the show (I believe the Ford Maverick hybrid is similar), it is the rear drive clutches that really caught me by surprise. Clearly the electromagnetic clutch couldn't carry a meaningful load, but using that clutch to make the ball ramp clamp the 'real' clutch is so mechanically simple that it is genius.
The pump drive is also quite clever.
That's an expensive transmission but should last almost forever. Even the clutches should see little wear since they won't really see meaningful slip. It looks like they could be replaced without splitting the case.
Thank you for another great video!
Thanks Bill!
Ford hybrids have generally used the same power-split hybrid approach as Toyota.
Another amazing video John!
We recently bought a 2022 KIA Sorento PHEV. I would like to see a video on the transmission.
I have driven the 2017 Chevy Volt PHEV, and A 2020 Rav4 Hybrid, but the 2022 KIA PHEV Sorento is different.
I notice that in EV Only mode it still shifts the 5 speed Automatic transmission, Kinda neat as this gives plenty of torque in 1st gear and also eases the RPM at highway speeds.
MFG states 32 miles on EV, but in Phoenix with the A/C on driving the freeways I can go 37 miles on EV only.
Thank you and Thanks for the suggestion!
You are the BEST!
@weberauto
Love your channel, thanks for everything you do. Im a hybrid technichian, I work at mobilityworks on wheelchair accessible vehicles. I work on a lot of Sienna hybrids, used to work on a lot of Honda IMA and own a Mitsubishi Outlander PHEV. Any plans to dive into Mitsubishi products? I think you would find Mitsubishi phev transmission interesting, in my opinion an ecvt is a better design and more efficient but its not a bad transmission. It's a gkn multimode etransaxle if your interested in learning more. You're the best John!
Thank you very much! No plans yet
Yes be great to see John do his deep dive into the Mitsi PHEV and it's VtoH (vehicle to home ) capabilities .
I'm so impressed with my 2014 Mitsi PHEV
(270K miles ,its still on the original 12KW battery) it's never let us down towing a heavy caravan, lot of the time of road , the Mitsi 4wd electric drivetrain is bomb proof , it has a 80 kw engine driven generator similar to Toyota RAV4 PHEV.
But we found when stationery in charge mode powering our off grid caravan via the 12 kw battery, it's more fuel efficient and quieter than our 10 hp honda generator in our experience.
A Bonus in charge Mode is we can heat and cool the caravan via a fan assisted ducting from the standard electric Mitsi PHEV AC/Heating
So impressed I've bought a 3rd Mitsi PHEV now 🙈
Thanks John for your great channel 👍
The Mitsubishi Outlander PHEV transaxle is functionally identical to the Honda i-MMD (or "E-Drive") that Dr. Kelly did about a year ago; however, it is constructed differently.
@@brianb-p6586 thanks for that, just enjoyed watching that again 👍.... but the main game changer with the original 2014 Mitsi PHEV is it's ability to charge V2H or V2G ( vehicle to Home/Grid) this is the main feature ( V2H) the 2019- 21 Honda still does NOT have V2H from the ICE ( Internal Combustion Engine) that's why it would enjoy the brilliant Dr Kelly doing his deep dive series on the Mitsi PHEV standard Charge Mode & V2H capabilities 😎👍
@@WeberAuto
th-cam.com/video/rntjceP-XPE/w-d-xo.html
Here's a simple explanation of gkn MMeT.
@24:54, regarding using both MG1 and MG2: correct, this system cannot use both MG1 and MG2 as motors to drive the vehicle without the engine running, because it is lacking the one-way clutch (as used in a Prius Prime for this purpose) which would be required to avoid spinning the engine.
It can use both MG1 and MG2 in a power-split mode, but in that case MG2 is generating, MG1 is motoring, all of the power to the wheels is going through the planetary gearset, and electrical power is recirculating from transaxle output to input to make this happen - it is an undesirable but possible mode of any input power-split transmission which occurs only when the relative engine and output speeds require it.
True
Wonder why there's no sprag clutch.
@@erik_dk842 sprag clutchs tend to fail
Again and again good cognitive lesson. Thank you professor John Kelly -you are my distance learning teacher. if possible make video abot Volksvagen ID4 and ID six please . Watching all your videos-Take care dear mr. Kelly .
Thank you very much for this video!
Very good video and excellently explained
fascinating and even I could understand it all!
Incredible, Thank you
This is exactly what I've been looking for! I've always been a fan of the 2019 plug-in Crosstrek & thought it was a fantastic collaboration of parts bins from the best of the two companies.
What I'm so immensely frustrated is why Subaru did NOT apply this to either a Forester, Legacy, or Ascent platform. You would have significantly more room to pack the lithium battery, achieve better EV-only range, and still retain the mechanical AWD system.
IF there was a PHEV Forester, it would really have been a killer to the Hyundai, Volvo, and BMW offerings - with a MUCH more capable AWD system for all road conditions. That, and it would've been a GREAT precursor for the RAV4 Prime instead of Toyota stealing the thunder with their late-released RAV4 Prime.
Thanks for sharing.
Your videos are next level to all the other "how does it work" ones!
Thank you very much!
Thank you for the effort to bring us the news. Outstanding presentation.
Great job ! 👍
Great video. Thank you.