I'm not sure if they still do it, but Tire Rack shaved a tire down to the same depth as my other tires when I got nail in the sidewall. The small cost to have it done is WELL WORTH not replacing all four.
Yup this is the way to go. If the other 3 tires still have a good amount of tread on them (enough tread such that it doesn't make sense to replace them yet) then getting a matching tire from Tire Rack and having them shave it down to the average of the other ties works wonders. I have personally done this in the past and have had no issues with any of the diffs. It hurts to take a brand new tire and have tread removed from it (unless you race a lot, and then I guess you are probably used to it), but it's cheaper than replacing all 4. That could be the difference of $300 vs $1000+. If your other tires don't have a lot of life left then you'd be better off just buying a new set - rather than $300 now and then another $1000+ 4 months later.
A difference in tire pressure which will also change your tire diameter. Considering the RPM of the tire, slight differences would also cause the same damage with more rotation (longer drive) based on this explanation. Kind of hard to believe it effects the center differential that easy as the traction control systems would kick in if 1 tire is rotating faster or slower. Is my traction control also damaging my center diff? I'd be surprised if there were any AWD cars around if this was the case. I usually change them as pairs (for traction purposes) and have been driving AWD cars in the past 20 years with no problems.
This is WRONG. Subaru specifications are that if you get a duplicate replacement tire with no more than 3/32 wear difference from your remaining tires, you can put it on your car. I just had this done a few days ago by a Subaru dealership and checked with them and got the word from the horse's mouth. The tech measured my tread and ordered me a new tire on the spot. They replaced my single tire because the wear difference from the new and the ones on the car were only 1/32 worn. 10/32 put on to a set of 9/32 is not a problem. It's specifically the transfer clutch system that Subaru mentioned in their TechTips publication for mechanics that relates to this issue. Sorry you don't know what you're talking about.
Can you explain on the STI how the +\- and manual mode works for the center diff. And how it can be utilized for street, track, auto cross, or even wet or dry conditions?
Not likely, because the tire wear you cause during track driving is temperature cycles. You can still have a lot of tread left, but the rubber won’t grip as good as new. The center differential is what they are talking about, not the transmission. FWD cars have differential is in the transmission though.
What about Toyota's E-Four system or Lincoln Corsair PHEV's AWD systems? I think they have an electric motor in the rear, but only electronically connected with the front axels. Do you still have to change all four tires when one tire popped?
Curious does it also depent on the AWD system, example like GM and their "On Demand" system. Also curious on the Honda systems. if this would still apply?
Thanks for your question. It does to an extent. Most AWD drivetrains connect all 4 wheels all the time. But if your system has an ability to disconnect one axle, it may be able to tolerate more of a tire size difference, but I would say it is unlikely. I'd defer there to whatever your owners manual says in that regard. Hope that helps and Stay Tuned!
Why would all 4 tires need replacement if one tire had a flat? A flat tire can often be repaired, but a tire flat has nothing to do with the tire's diameter. The important thing is all 4 tires having very close to the same diameter, so they will all rotate at very close to the same speeds.
Thanks for the comment. That is a good point. As long as you are using the stock size tires, the spare should be fine, but if you are running larger or smaller tires than stock, the spare may well not be correct. Thanks for watching and Stay Tuned!
on my 2011, the undersize spare wheel goes on the rear axle, and speed is to be kept under 40?mph. So there's a hint there: if you can only afford 2 new ones, put 'em on the front and keep your speed low to keep the central diff cool.
So if just one thirty seconds of an inch can be problematic . Does the increased wear on the front tires of my track car pose a problem with the center diff when I move them to different positions on the car ? Was surprised at how little it takes to cause an issue .
Thanks for your question. 1/32 is the maximum recommended difference. The best way to think of it is that if the difference increases more than that, that is the point where issues may start to arise. Most normal tire wear on track shouldn't create an issue, but it is certainly something to keep an eye on it. Thanks for watching and Stay Tuned!
Its really BS that the auto manufacturers can't have the computer compensate. Imagine you get a flat and all of a sudden your hit with a $800+ bill for new tires. Friggin blows.
Had 2 all wheel drive suv's escape and kia Sorrento with different tread depth same size tires and drove for thousands of km no issues whatsoever. I'm not going to chance all 4 because of one tire that's a tire company scam as far as I'm concerned
I have a question unrelated to this video….I’ve exhaustively searched for the answer. On a 2008 STI, do I need to remove the turbo in order to get to the banjo bolt on the oil feed line to the turbo? I don’t see any other way to do it. Any help would be appreciated. Thanks.
Thanks for your question John. No, you should not need to remove the turbo to get the banjo bolt on the turbo oil-feed line. Do you have an aftermarket turbo? If you do, often times, you need a flexible oil feed line to work with the larger center section, etc. www.flatironstuning.com/blouch-turbo-braided-oil-feed-line-2 Hope that helps and Stay Tuned!
@@FlatironsTuning Thanks for the response. The banjo bolt for the turbo sits horizontally on the block underneath the intake for the turbo. I tried last night for a couple of hours and couldn’t get to it. Any suggestions as far as what sort of wrench would work the best? I’d hate to have to remove the turbo just to get to that bolt. It’s almost as dumb of a spot as the one behind the timing cover is. Why Subaru!? Lol. Any help would be appreciated. Also, any of the Tokyo Roki filters come in yet?
I had a flat yesterday, pothole (inside side wall ripped, no hope for repair), Front right tire, 215/50/17. I didn't had a spare one.. i called a service and they relocate my rear right one to front right, and put a spare 225/50/17 on rear right. So, 10mm wider from other 3. I drove to home very carefully, and affraid of some sort of disbalance and etc, but everything went well (including a highway driving in 6th gear, without any shaking or similar) I purchase one new tire same model as other three. Other three are relatively new (about 8000km) and my tire servicer advised to buy one new and put it on back with other that have maximum thread. So, I think that even 225 with three 215 tires don't seem to be a problem... I don't know. Any advice? Thanks
Thanks for your question. On an All Wheel Drive Car, replacing 2 tires is just as bad as replacing 1. If you don't have all 4 tires within spec, it can wear or damage a center differential. Hope that helps and Stay Tuned!
I don't know if I'm doing right. I have a 2004 wrx and since I have a abnormal income I usually broke. I always buy them in pairs like 1 week 2 tires and next week I buy the other two
What does "mismatched size" mean? Do you mean literally mean a different profile/size (e.g. 17") or do you mean the same tire with a new (deeper) tread depth? Be precise with your language. If it is tread depth, then clearly replacing 1 flat amongst a set of 4 that are two months' old is okay. As such, how little tread depth with the remaining 3 is too little that would cause an unacceptable difference with the new, deeper tread depth, tire? Also, what about replacing two tires on one axle (i.e., the front) while leaving other axle with the same old (i.e., still good rear) tires?
Thanks for your question. For this topic, we are talking about the same tire size, but with a difference in tread depth. If you have an All-Wheel Drive car, you do need to replace all 4 tires. Putting two new tires on an axle will cause about as much issue as putting on a single new tire. Thanks for watching and Stay Tuned!
@@FlatironsTuning Thank you very much for your reply. It was helpful but still seeking a complete answer: It would appear that replacing 1 flat amongst a set of 4 that are two months' old would not be detrimental (because of almost no treadwear). As such, how little tread depth with the remaining 3 is too little that would cause an unacceptable difference with the new, deeper tread depth, tire?
It is still confusing because other experts say you do not have to replace all four tires. It is mind boggling to me that a car would be designed to have people replacing all four tires on a car just because one tire has a nail in it. I live in the city and I get nails all the time. So Sam’s Club went from having to replace two tires at one time to having to replace four at one time. So the biggest problem excuse is an all wheel drive. People cannot afford to purchase tires in this manner. Not when I can get nails in tires several times a year. And what’s wrong with patching a tire these days? This absolutely ludicrous!
Wrong! Wrong! Wrong! First, let’s begin with an obvious truth. No, you should never have four different tires at four different levels of wear on the same vehicle… EVER. It’s dangerous from a handling, braking, and traction point of view. PERIOD! That said, it’s a car! Not a Swiss clockwork. In the vehicle is something called a differential. It allows the wheels to turn at a “different rate”. If you did not have a differential, you could not turn the vehicle because when the car goes around a turn, the wheels on the outside of the turn HAS TO travel farther than the wheels on the inside of the turn. The car doesn’t know that it’s turning. It just automatically adjusts using the differential. Now, if the tire on one wheel is 1/4 inch larger in diameter than the wheels on the other side of the car, this is exactly the same as driving in a circle of a particular radius. The car just thinks it’s turning.
AGAIN .. COMLETE B.S. So if the issue is that the differential is "turning" due to the difference in diameter (and we're talking about 32's correct, which is literally nothing per rotation) then I shouldn't take any corners when I drive? My god.. the vehicle's differentials are going to be destroyed by literally nothing noticeable while driving my vehicle in a straight line, but somehow, magically, when I make a sharp or slow turn to the right or left (where the outside tires turns DRAMATICALLY more than the inside tire) that's ok. Thank god the differential can "differentiate" between the two scenario's. I'm so tired of idiots like yourselves shoving this misinformation to the public who is not educated. PURE SALES DRIVEN!!!!!!!!!!
No, they’re right but they’re wrong about WHY. The cars they’re talking about (I have two of them myself) do not have a center differential. They have a center multiplate clutch that’s almost always ON and therefore would drag if there were speed diffs happening all the time between front and back. And those clutch packs aren’t usually cooled. Subaru and Honda both work this way.
I'm not sure if they still do it, but Tire Rack shaved a tire down to the same depth as my other tires when I got nail in the sidewall. The small cost to have it done is WELL WORTH not replacing all four.
Thanks for the comment. Yes, Tire Rack still does this I believe.
Thanks for watching and Stay Tuned!
Yup this is the way to go. If the other 3 tires still have a good amount of tread on them (enough tread such that it doesn't make sense to replace them yet) then getting a matching tire from Tire Rack and having them shave it down to the average of the other ties works wonders. I have personally done this in the past and have had no issues with any of the diffs. It hurts to take a brand new tire and have tread removed from it (unless you race a lot, and then I guess you are probably used to it), but it's cheaper than replacing all 4. That could be the difference of $300 vs $1000+. If your other tires don't have a lot of life left then you'd be better off just buying a new set - rather than $300 now and then another $1000+ 4 months later.
A difference in tire pressure which will also change your tire diameter. Considering the RPM of the tire, slight differences would also cause the same damage with more rotation (longer drive) based on this explanation. Kind of hard to believe it effects the center differential that easy as the traction control systems would kick in if 1 tire is rotating faster or slower. Is my traction control also damaging my center diff? I'd be surprised if there were any AWD cars around if this was the case. I usually change them as pairs (for traction purposes) and have been driving AWD cars in the past 20 years with no problems.
Yes, yes, yes! It’s called a differential for a reason!
This is WRONG. Subaru specifications are that if you get a duplicate replacement tire with no more than 3/32 wear difference from your remaining tires, you can put it on your car. I just had this done a few days ago by a Subaru dealership and checked with them and got the word from the horse's mouth. The tech measured my tread and ordered me a new tire on the spot. They replaced my single tire because the wear difference from the new and the ones on the car were only 1/32 worn. 10/32 put on to a set of 9/32 is not a problem. It's specifically the transfer clutch system that Subaru mentioned in their TechTips publication for mechanics that relates to this issue.
Sorry you don't know what you're talking about.
One of my barely used Falken wildpeak had a nail near the sidewall on my AWD cx5, I had to replace the whole set.
Some manual says it is best to replace all and yet says you can replace them as pairs also.If it says that save some money.
Can you explain on the STI how the +\- and manual mode works for the center diff. And how it can be utilized for street, track, auto cross, or even wet or dry conditions?
That is a great question. We'll add it to the list!
Thanks for watching and Stay Tuned!
So if you race an AWD on an oval track (and the outer wheels are always traveling further/turning faster) that will ruin the transmission?
Not likely, because the tire wear you cause during track driving is temperature cycles. You can still have a lot of tread left, but the rubber won’t grip as good as new.
The center differential is what they are talking about, not the transmission.
FWD cars have differential is in the transmission though.
What about Toyota's E-Four system or Lincoln Corsair PHEV's AWD systems? I think they have an electric motor in the rear, but only electronically connected with the front axels. Do you still have to change all four tires when one tire popped?
Curious does it also depent on the AWD system, example like GM and their "On Demand" system. Also curious on the Honda systems. if this would still apply?
Thanks for your question. It does to an extent. Most AWD drivetrains connect all 4 wheels all the time. But if your system has an ability to disconnect one axle, it may be able to tolerate more of a tire size difference, but I would say it is unlikely.
I'd defer there to whatever your owners manual says in that regard.
Hope that helps and Stay Tuned!
Can you just buy the same tire same brand for a tire that was blown out?
Why would all 4 tires need replacement if one tire had a flat? A flat tire can often be repaired, but a tire flat has nothing to do with the tire's diameter.
The important thing is all 4 tires having very close to the same diameter, so they will all rotate at very close to the same speeds.
I think you should also mention about spare wheel. To check it size.
Thanks for the comment. That is a good point. As long as you are using the stock size tires, the spare should be fine, but if you are running larger or smaller tires than stock, the spare may well not be correct.
Thanks for watching and Stay Tuned!
@@FlatironsTuning you have awesome content! Best wishes from Poland!
on my 2011, the undersize spare wheel goes on the rear axle, and speed is to be kept under 40?mph.
So there's a hint there: if you can only afford 2 new ones, put 'em on the front and keep your speed low to keep the central diff cool.
So if just one thirty seconds of an inch can be problematic . Does the increased wear on the front tires
of my track car pose a problem with the center diff when I move them to different positions on the car ?
Was surprised at how little it takes to cause an issue .
Thanks for your question. 1/32 is the maximum recommended difference. The best way to think of it is that if the difference increases more than that, that is the point where issues may start to arise.
Most normal tire wear on track shouldn't create an issue, but it is certainly something to keep an eye on it.
Thanks for watching and Stay Tuned!
Its really BS that the auto manufacturers can't have the computer compensate. Imagine you get a flat and all of a sudden your hit with a $800+ bill for new tires. Friggin blows.
Had 2 all wheel drive suv's escape and kia Sorrento with different tread depth same size tires and drove for thousands of km no issues whatsoever. I'm not going to chance all 4 because of one tire that's a tire company scam as far as I'm concerned
there's tire shops out there offering a tire match, i.e. they keep a ton of stock
Thanks for the comment, and thanks for watching.
Stay Tuned!
I have a question unrelated to this video….I’ve exhaustively searched for the answer.
On a 2008 STI, do I need to remove the turbo in order to get to the banjo bolt on the oil feed line to the turbo? I don’t see any other way to do it. Any help would be appreciated. Thanks.
Thanks for your question John. No, you should not need to remove the turbo to get the banjo bolt on the turbo oil-feed line.
Do you have an aftermarket turbo? If you do, often times, you need a flexible oil feed line to work with the larger center section, etc.
www.flatironstuning.com/blouch-turbo-braided-oil-feed-line-2
Hope that helps and Stay Tuned!
@@FlatironsTuning Thanks for the response. The banjo bolt for the turbo sits horizontally on the block underneath the intake for the turbo. I tried last night for a couple of hours and couldn’t get to it. Any suggestions as far as what sort of wrench would work the best? I’d hate to have to remove the turbo just to get to that bolt. It’s almost as dumb of a spot as the one behind the timing cover is. Why Subaru!? Lol. Any help would be appreciated.
Also, any of the Tokyo Roki filters come in yet?
I had a flat yesterday, pothole (inside side wall ripped, no hope for repair), Front right tire, 215/50/17.
I didn't had a spare one.. i called a service and they relocate my rear right one to front right, and put a spare 225/50/17 on rear right. So, 10mm wider from other 3.
I drove to home very carefully, and affraid of some sort of disbalance and etc, but everything went well (including a highway driving in 6th gear, without any shaking or similar)
I purchase one new tire same model as other three. Other three are relatively new (about 8000km) and my tire servicer advised to buy one new and put it on back with other that have maximum thread.
So, I think that even 225 with three 215 tires don't seem to be a problem... I don't know.
Any advice? Thanks
What about just changing 2 tires like both front or both rear? Is that just as bad as replacing 1 trie, or is it better?
Thanks for your question. On an All Wheel Drive Car, replacing 2 tires is just as bad as replacing 1. If you don't have all 4 tires within spec, it can wear or damage a center differential.
Hope that helps and Stay Tuned!
What about replacing JUST TWO?! Like the right and left front tire.
How about in a 4wd sub
I don't know if I'm doing right. I have a 2004 wrx and since I have a abnormal income I usually broke. I always buy them in pairs like 1 week 2 tires and next week I buy the other two
More than likely your manual says all 4
What does "mismatched size" mean? Do you mean literally mean a different profile/size (e.g. 17") or do you mean the same tire with a new (deeper) tread depth? Be precise with your language.
If it is tread depth, then clearly replacing 1 flat amongst a set of 4 that are two months' old is okay. As such, how little tread depth with the remaining 3 is too little that would cause an unacceptable difference with the new, deeper tread depth, tire?
Also, what about replacing two tires on one axle (i.e., the front) while leaving other axle with the same old (i.e., still good rear) tires?
Thanks for your question. For this topic, we are talking about the same tire size, but with a difference in tread depth.
If you have an All-Wheel Drive car, you do need to replace all 4 tires. Putting two new tires on an axle will cause about as much issue as putting on a single new tire.
Thanks for watching and Stay Tuned!
@@FlatironsTuning Thank you very much for your reply. It was helpful but still seeking a complete answer:
It would appear that replacing 1 flat amongst a set of 4 that are two months' old would not be detrimental (because of almost no treadwear).
As such, how little tread depth with the remaining 3 is too little that would cause an unacceptable difference with the new, deeper tread depth, tire?
It is still confusing because other experts say you do not have to replace all four tires. It is mind boggling to me that a car would be designed to have people replacing all four tires on a car just because one tire has a nail in it. I live in the city and I get nails all the time. So Sam’s Club went from having to replace two tires at one time to having to replace four at one time. So the biggest problem excuse is an all wheel drive. People cannot afford to purchase tires in this manner. Not when I can get nails in tires several times a year. And what’s wrong with patching a tire these days? This absolutely ludicrous!
@@lisaadams780 agreed. They are vague in their answers and imprecise
I really think the difference is negligible
Wrong! Wrong! Wrong!
First, let’s begin with an obvious truth. No, you should never have four different tires at four different levels of wear on the same vehicle… EVER. It’s dangerous from a handling, braking, and traction point of view. PERIOD!
That said, it’s a car! Not a Swiss clockwork. In the vehicle is something called a differential. It allows the wheels to turn at a “different rate”. If you did not have a differential, you could not turn the vehicle because when the car goes around a turn, the wheels on the outside of the turn HAS TO travel farther than the wheels on the inside of the turn. The car doesn’t know that it’s turning. It just automatically adjusts using the differential.
Now, if the tire on one wheel is 1/4 inch larger in diameter than the wheels on the other side of the car, this is exactly the same as driving in a circle of a particular radius. The car just thinks it’s turning.
AGAIN .. COMLETE B.S. So if the issue is that the differential is "turning" due to the difference in diameter (and we're talking about 32's correct, which is literally nothing per rotation) then I shouldn't take any corners when I drive? My god.. the vehicle's differentials are going to be destroyed by literally nothing noticeable while driving my vehicle in a straight line, but somehow, magically, when I make a sharp or slow turn to the right or left (where the outside tires turns DRAMATICALLY more than the inside tire) that's ok. Thank god the differential can "differentiate" between the two scenario's. I'm so tired of idiots like yourselves shoving this misinformation to the public who is not educated. PURE SALES DRIVEN!!!!!!!!!!
No, they’re right but they’re wrong about WHY. The cars they’re talking about (I have two of them myself) do not have a center differential. They have a center multiplate clutch that’s almost always ON and therefore would drag if there were speed diffs happening all the time between front and back. And those clutch packs aren’t usually cooled. Subaru and Honda both work this way.
Ah ha! A man who understands geometry!