Awd and tire wear

[discopedro]

I'm sitting hear at discount tire getting a tire repaired and I hear him talking to a customer about changing a tire. I guess the guy has a Porsche cayenne and the tire jockey is telling him he can't just change 1 tire he has to change them all due tread wear differences my cause the trans, diff etc to blow up due to difference in the other old tires tread wear. .......I'm guessing this is all bullshit....right?

 

[knewsom]

Re: Awd or tire wear

I'm sitting hear at discount tire getting a tire repaired and I hear him talking to a customer about changing a tire. I guess the guy has a Porsche cayenne and the tire jockey is telling him he can't just change 1 tire he has to change them all due tread wear differences my cause the trans, diff etc to blow up due to difference in the other old tires tread wear. .......I'm guessing this is all bullshit....right?

In terms of the Cayenne, I have no clue - but I have heard accounts of Subarus having diff trouble because of incorrect tire pairings. In fact, I recall specifically a story our station covered where a local man bought a Subaru from a dealership that had either changed just one tire, or had put one or two different kinds of tires on the car, and within a month his diff was toast - but the dealership wouldn't fix it even though it was their fault. After we put together the story, they made it right.

 

[az_max]

Re: Awd or tire wear

different tire sizes yes. One worn to bald and a new tire of the same size... questionable. There is a differential there to let one tire rotate faster as needed. The .01% difference in diameter from a new tire to a worn tire? I wouldn't think it would upset an AWD car.

 

[clarkwjackson]

Most awd cars allow for 3-4% of the circumference. Suby is famous for drivetrain problems and chrysler pacifica (with regards to mixing full depth tire and worn tires in service). Some are more picky than others. When I first heard about this I asked the guys at the local stealership and they told me the disco has so much slop in the drivetrain it wouldn't make much difference.

 

[KyleT]

its not ideal, but there shouldn't be an issue with just 1 tire being replaced. but it depends on the wear and liability.

 

[mjbrox]

I was told with my Audi that you had to replace them all at once.

So with such an expensive car, I think the Tire Jockey is right

 

[mjbrox]

Re: Awd or tire wear

- but I have heard accounts of Subarus having diff trouble because of incorrect tire pairings.

it is always Subarus and Apple with you.

 

[LR Max]

X2 on the Subaru thing. I had a Subaru and that is what I always heard.

 

[knewsom]

Re: Awd or tire wear

it is always Subarus and Apple with you.

:rofl: Funny, if you ask my wife, she'll say it's always boobs, guns, and Rovers with me...

 

[dcarr1971]

Most awd cars allow for 3-4% of the circumference. Suby is famous for drivetrain problems and chrysler pacifica (with regards to mixing full depth tire and worn tires in service)...

Sorry, but I have to call bullshit on this assertion about Subaru. I've owned at 4 since 1989...all were AWD and their drivetrains have always been bulletproof with nothing more than oil changes and scheduled maintenance out beyond 200k miles.

The tire shop guys are probably either crooks or illiterate, so they just tell everyone with a AWD car that they need to do all 4 tires at once. Ideally you would replace them in pairs (i.e.- both front, both rear, etc.) so that each diff has both sides spinning at the same rate, but even this is not mandatory.

Over the last 20 years and nearly 750k miles and counting between my 4 Subies I've had to replace quite a few tires one at a time and have never had a problem in one of my AWD Subaru's.

 

[discopedro]

Well, I'm in Vegas and people are a lil shifty out here.

 

[no694terry]

i've had 3 subaru outbacks, a 2.5 rs and a impreza outback. Only one of my outbacks didn't like tires that weren't perfect, it would bind and clunk unless every tire was with a mm of each other, my current beater outback will run a wheel barrel tire, a tractor tire and two semi truck tires and not even phase it. i replaced a center vc in my 2.5rs and in my current outback, but think it was more from beating beet on.

i guess every cars different and im sure diff type has a lot to do with it, open diff are probably more friendly to mismatched diameters than a locker or viscous unit. the porsche probably has some sort of lsd that would not get along with mismatched tires

 

[knewsom]

i've had 3 subaru outbacks, a 2.5 rs and a impreza outback. Only one of my outbacks didn't like tires that weren't perfect, it would bind and clunk unless every tire was with a mm of each other, my current beater outback will run a wheel barrel tire, a tractor tire and two semi truck tires and not even phase it. i replaced a center vc in my 2.5rs and in my current outback, but think it was more from beating beet on.

i guess every cars different and im sure diff type has a lot to do with it, open diff are probably more friendly to mismatched diameters than a locker or viscous unit. the porsche probably has some sort of lsd that would not get along with mismatched tires

I was thinking LSD as well.

What year Outback was it that wouldn't tolerate the different tires?

 

[no694terry]

I was thinking LSD as well.

What year Outback was it that wouldn't tolerate the different tires?

97 with the 4EAT

 

[C Ross]

I just sold our 2006 Cayenne S on it with 130K miles. Two at a time tire changes maybe, but all four is some bullshit straight out of a dealership. This tire guy has a future ahead of him at some high end dealership as a service manager.

BTW, other than the coolant pipe failure it was a very reliable 130K mile performance suv. If it only had a third row seat option we would have another one in a heartbeat.

Ross

 

[discopedro]

Ya, no shit! The best part was hearing the tire guy tell him(customer) he'd have to sign a waiver before the did the work. The owners looked like eastern european mafia and weren't to happy to hear this load of shit.

 

[flyor]

Also have to be aware that the tire load rating is correct. I have seen a number of cases where the tire brand, tread, size have been identical but the load rating was different causing issues with ESP light coming on.

 

[gmookher]

Sorry, but I have to call bullshit on this assertion about Subaru. I've owned at 4 since 1989...all were AWD and their drivetrains have always been bulletproof with nothing more than oil changes and scheduled maintenance out beyond 200k miles.

The tire shop guys are probably either crooks or illiterate, so they just tell everyone with a AWD car that they need to do all 4 tires at once. Ideally you would replace them in pairs (i.e.- both front, both rear, etc.) so that each diff has both sides spinning at the same rate, but even this is not mandatory.

Over the last 20 years and nearly 750k miles and counting between my 4 Subies I've had to replace quite a few tires one at a time and have never had a problem in one of my AWD Subaru's.

x2, tho I replace in pairs to prevent pulling.

 

[97discox2]

Picked up my RRC after giving them a set of tires to mount. Unaware that i gave them my two 245-75's from my D1 and two235-70's. they put the 245's on the rear. Crazy ride front tires chirping at high speeds. Lot of fun.