Diesel Electric Hybrid?
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- เผยแพร่เมื่อ 9 ก.พ. 2025
- There was a hybrid diesel race car, the Audi R18, and it was a really good race car. But there’s not a street car with this same setup. Let’s talk about why. First we need to understand the characteristics of the individual motors and what the general consumer enjoys in a vehicle. A diesel is high torque at low RPM, but torque drops off pretty significantly at higher RPM, which is very similar to an electric motor. However, an internal combustion engine torque is pretty poor at low rpm, but can go to a much higher RPM, giving that engine quite a bit of power. And what a consumer enjoys is an overall balanced approach - they want to feel torque at low engine rpm, but they also don’t want to feel as if they’re losing power at high rpm. And so you can see how an electric motor and an ICE make a great combination in a hybrid, where the electric motor and combustion engine spin at the same speed. At low RPM the electric motor provides torque, and at high rpm the ICE creates power to make up for the drop off in torque from the electric motor. Combining a diesel and an electric motor would give a huge amount of torque at low RPM, but you’ll either be shifting gears a lot or change gear ratios and run out of steam at higher RPM. Additionally, with a ton of low end torque, 99.9999% of drivers can’t realistically handle it. If you combined the power plants for a Golf Electric and a Golf Diesel, you make 450lbft of torque, maybe 430 with efficiency losses. A Mustang makes 400 lbft of torque and drivers can’t handle it. So for a vehicle being sold to consumers, it just doesn’t make sense trade off a balanced power delivery for low end torque that’s unusable.
Except there have in fact been several mass produced diesel hybrids... The reason it isn't common is only because of cost and weight. diesel is inherently more efficient which is the primary reason people buy hybrids, so its been tried. But, diesel engines are heavy and so are hybrid transmissions, electric motors, and batteries. So a diesel hybrid is VERY heavy, which means heavier steering, brakes, frame, ect. Diesel engines are also more expensive so what you end up with is a slow, heavy, expensive car competing with a lighter, faster, cheaper alternative. So they dont sell. The drivability of such a setup is not terribly difficult to solve, economics and weight are.
Liked the presentation though. Just disagree with the argument.
It’s probably a mixture of both economics and drivability
@@drive.science I don't understand why drivability is a concern. Adding an electric motor to a diesel engine only accentuates its strengths, and those strengths are why they became popular in the first place.
You'll simply have an engine which needs to rev even less than a traditional diesel which improves on the diesel's inherent efficiency even further. You get some pretty hilarious fuel consumption figures.
And if anything, it'll be _more_ drivable for most people in regular traffic since you're sitting on a large amount of power all the time.
If there's a concern to be had (aside from the initial cost, of course) it's reliability, because people will use them over short trips and the engine will have even less opportunity to get up to temperature with the electric motor helping out.
@@xIcarus227when you run 2 things in parallel, you want complementing strengths
@@drive.science says who? Min-maxing isn't an invalid approach, and many people appreciate it.
It's entirely subjective and neither approach is bad.
Why are you using the terms "diesel" and "ICE" as if they aren't the same thing? A Diesel IS an internal combustion engine, just like a gasoline engine is an ICE. Also diesel hybrids are common af in Europe.
Diesel hybrid in a sedan/suv is a blessing.
You don't need to heat cycle the engine for short city traffic drives and you get amazing range long distance
I do like the way you put this idea together. While yes if I leave my engine and motor attached to the same drivetrain then I would lose a lot of upper end power BUT let’s separate the two. I have my diesel engine, a small one which is extremely efficient and have it running a generator and that’s it. The motor is connected to a 10-12 speed transmission built for maintaining RPM’s in the high torque band of the electric motor at the many speeds that we use often. Pair that generator/motor combination with a smaller battery like a hybrid and we would now have an electric hybrid vehicle that has a built in range extender which is super efficient on fuel with the feel of being an all electric vehicle minus the engine noise and Diesel input rather than battery power. The benefits are that you have more efficient cars now because your engine can be as small as possible and operate at the perfect RPM for torque/power production all the time rather than changing rpm’s constantly, a torquey car that would honestly be able to replace the pickup truck pretty easily, and all of this utilizes the same infrastructure we already have. I believe there’s a company under the name of Edison Motors making semi’s like this who are also releasing retrofit kits for pickups soon if you’d like some more information. It’s not an argument, I love all ideas on these sort of topics and would love to hear of any other companies working on some crazy hybrid/electric/ice technology if anyone knows of any
You basically described what’s called a range extender hybrid or a series hybrid, and is a great all-rounder. Another tech that is really cool is Koenigsegg Direct Drive, which is a hybrid drive that eliminates the transmission
And now Edison Motors are about to sell retrofits to turn one ton trucks into diesel electric hybrids.
Volvo D6 springs to mind, and I'd have thought that getting the torque delivery right would be a matter of gearing. They are certainly rare though
I don't get the Mustang comparison, torque isn't the reason Mustangs are hard to handle. Quite the opposite actually, they have NA engines with a linear power curve and predictable response which makes it easy to estimate what the car's gonna do when you accelerate. Compare that to the popular small-displacement turbo engines which have a hefty amount of lag, they have a much higher chance of surprising the driver due to the torque surge.
Mustangs of yore were hard to handle primarily due to how nose heavy they were (still are somewhat, the V8 at least) and due to the poor suspension setup. But the last 2 generations have been much better in these regards so if someone can't handle a modern Mustang I'd honestly call it a skill issue. The 2015+ models are so much friendlier, though indeed not as friendly as something with a 50/50 weight distribution.
My guy, your video is chock-full of errors and is frankly misleading. First of all, a diesel engine _is_ an internal combustion engine, so it doesn’t make sense that you referred to them as separate things. Second of all, the torque curve of a diesel engine doesn’t really matter when interfacing with an electric motor, since you can simply change it with a gear ratio. In a hybrid powertrain, there are multiple ways to interface the combustion engine and the electric motor: parallel, like in the Audi race car and most hybrid sports cars; series, like in the BMW i3 and in diesel-electric locomotives; or power-split (both parallel and series) like in a Toyota Prius. In parallel hybrids, the electric motor is chosen to be tailored to the characteristics of the combustion engine, and if needed, a gear ratio can be added between the two motors so that their useful RPM ranges complement each other. And in series and power-split hybrids, the torque curve of the combustion engine doesn’t even matter at all, since the engine can spin at any RPM independently of the wheels.
So, why is it that diesel engines rarely get used in hybrid passenger vehicles? Well, because even though they are a bit more fuel-efficient than gasoline engines, they are produce many times more toxic emissions, and the equipment required to filter said emissions adds significant cost and complexity to the vehicle, so in most cases it’s not worth in in a hybrid. It is worth noting though that for larger vehicles, such as busses and trains, a diesel engine _is_ the favoured choice for a hybrid powertrain because for a vehicle of that size, the cost of an emissions filtering system is pretty small compared to the overall cost of the vehicle. It is for this reason that most hybrid busses and trains are diesel. In fact, the deisel-electric powertrain is so good for trains that you’d be hard-pressed to find an internal combustion engine locomotive that _isn’t_ a diesel-electric hybrid.
Well you started out insultingly, but you do bring up some good points. Yes they existed - not currently. Yes it’s more complex - not enough to deter the idea from existing. Yes electric motors are tailored to the application - but an electric motor will always have a similar torque curve. You can’t out-engineer science.
There is some part of it that comes down to gear ratios and application. Locomotives and buses need a lot of torque, and aren’t designed for speed. They can sacrifice top-end acceleration without a downside - it takes them 30 seconds to go 0-60. That would be unacceptable in a passenger vehicle, but when you need to get 10+ tons moving, that torque is a huge benefit. When you need to move
Nice videos, short and to the point
This video is in fact completely wrong. There have been lots of productiom diesel hybrids such as.
Audi A6, A8, Q7 and Q8,
BMW 320D and X7,
Hyundai Tucson,
Kia sportage
Land rover, range rover, discovery and defender
Mercedes 300de models (C class, E class)
Volvo v60, V90 and XC60.
And these are just the few I could remember at this moment, there are many more
And what they all have in common is they’re out of production
@@drive.science Landrover range rover and defender + mercedes gle and bmw x7 are still available 2023/24 models with diesel hybrid systems
What about diesel engine battery and 12 speed automatic transmission