My first non awd drive car in a long time.

[Tuckerman]

We have a new VW Sportwagon TDi well we bought it in Feb of 2012. My wife ran over a board full of nails and shredded the back tire off the car. In the past when I had to replace a tire on a Subaru I had to do all 4 but the TDi is not awd so can I just replace the one?

[trex_9]

you do realize that when one tire goes (flat, shredded, otherwise) out you don't have to replace all 4, regardless of AWD or not.

-Subaru owner for the last 12 years

[bfree]

If they're that new, you can probably get away with just changing the one. But the general advice will be to replace both of the rears.

[Pat]

How many miles are on the other good rear tire? If there is little wear, you can just replace with a new one. If there is any significant wear you can buy a new tire, have it shaved to the matching tread depth, mounted and balanced. The Tire Rack can get you what you need and shave to the proper depth if necessary. Then they can ship it to the installer of your choice.
FWD cars aren't as finicky as AWD cars regarding matching tread depth, but it's still a good idea to keep things similar on the same axle.

[Tuckerman]

lol awd drive

[jerr]

Effectively, I just did exactly this - brand new tires on the rear in Feb, death puncture week before last.

I replaced just the one. No conversation or thought about doing the other one at all.

Fyi; done about 10,000km on the rear tires, subi, awd and I never do all tires at once, although I'll often do both frnt/bck at the same time when they've worn out.

Although, always replacing all tires on awd/4wds holds water theoretically, it doesn't standing up pragmatically.

[Pat]

This is incorrect:
"Although, always replacing all tires on awd/4wds holds water theoretically, it doesn't standing up pragmatically."

Differentials can be ruined with significantly different tread depths.

[kbahus]

It's hard on the viscous coupler in the transmission and can ultimately destroy it, that is why they recommend all 4.

[ferniebiker]

I'm pretty sure it's the transfer case that can be damaged when you have different sized tires.

[jerr]

This is incorrect:
"Although, always replacing all tires on awd/4wds holds water theoretically, it doesn't standing up pragmatically."

Differentials can be ruined with significantly different tread depths.

Have you ever seen this happen? I never have, and I've never replaced all the tires on any of my awds in 15+ years. Both personal and a small fleet of 4wds that fell under my care for 2.5 years.

To be clear, I also wouldn't run significantly different tread depths, but I wouldn't consider half a years average wear to be significant (I'm making the assumption the car was brought from new, thus new tires).

If you want to spend 4 times as much money, be my guest. But personally, I don't think it's necessary.

[kbahus]

I have seen Subaru viscous couplers go bad (also known as the center differential) so it's not like they are indestructible. I would guess around a $1k repair bill to replace, it's been a while since one has come through the shop and don't remember exactly.

Mismatched tire models, brands, and sizes are a sure way to kill it as well as different tread depths. How far you can go on the tread depth variation I couldn't say for sure but I would think 2-3/32nds should not hurt it. The biggest problem is different brand tires, the same size tire and a different manufacturer will have drastically different rolling diameters.

[XXX-er]

We have a new VW Sportwagon TDi well we bought it in Feb of 2012. My wife ran over a board full of nails and shredded the back tire off the car. In the past when I had to replace a tire on a Subaru I had to do all 4 but the TDi is not awd so can I just replace the one?

did the car come with a space saver or a real spare tire, they used to be real spares ?

If you got a real spare you could put the new tire on the car with the spare (which is a I assume new) and make the slightly used rear the spare

IME running MK4 VW's the tires are not going to wear evenly anyway cuz the fronts wear faster but having the same tire wear for the tires on an axle is a good idea

[davieboot]

I have seen Subaru viscous couplers go bad (also known as the center differential) so it's not like they are indestructible. I would guess around a $1k repair bill to replace, it's been a while since one has come through the shop and don't remember exactly.

Mismatched tire models, brands, and sizes are a sure way to kill it as well as different tread depths. How far you can go on the tread depth variation I couldn't say for sure but I would think 2-3/32nds should not hurt it. The biggest problem is different brand tires, the same size tire and a different manufacturer will have drastically different rolling diameters.

I have seen this happen also, but due to different brands being slightly different actual size, though they were both the same listed size. That was enough to convince me that it could also happen if tires are worn sufficiently.

[Tuckerman]

Looking at the tire last night when she got home I could not find any puncture holes, and it appears that a belt just broke. I don't think they can repair this but this also should not happen.





I have to bring the car in Friday because the body panels are so tight that the paint on the door is wearing off rubbing against the rubber from the rear door.

Back of front door.


This is the rubber from the rear door you can see where its scuffed.

[kbahus]

Usually when a tire comes apart like that it was driven on with low air, at some point in it's life. Does that car have tpms? What brand tire?

[XXX-er]

deja vu all over again, I did much the same thing coming down from the ski hill, destroyed a nokian snow tire that was almost done anyway but then i couldn't get the wheel off because the rim had siezed to the hub, no cell service, a tow would cost 100$ while a lunched steel rim is only 50$ and the tire is facked anyhow SO drive 20kms to the tire store

The VW drives ok on a rear flat up to about 20KPH but its pretty noisey till the belt comes off and you are just on the rubber left on the bead like in your picture, the rubber left on my rim protected the rim enough that I was able to reuse the rim no problem

you should get some warranty on that tire

be aware steel rims can seize to the hub in <6months , the rim/hub fit is VERY TIGHT and really the nuts are only holding the wheel from rotating on the hub

[Tuckerman]

My wife was doing 80 mph on the highway.

[XXX-er]

at highway speed you usually destroy the tire just like that

[Tuckerman]

Dealer says tire is not their problem. I ask if the other tires were safe he says he can't say that they are. Car in not even a year old.

Sent from my SCH-I535 using TGR Foru

[PNWbrit]

I don't think they can repair this

No shit.....

[MakersTeleMark]

be aware steel rims can seize to the hub in <6months , the rim/hub fit is VERY TIGHT and really the nuts are only holding the wheel from rotating on the hub

Another reason why carrying a big fucking tool in the trunk is a good idea. I always carry one, along with a very stout screwdriver and a can of pb blaster. They have all come in handy numerous times.

[XXX-er]

Dealer says tire is not their problem. I ask if the other tires were safe he says he can't say that they are. Car in not even a year old.

Sent from my SCH-I535 using TGR Foru

Doesn't sound like yer dealer is much of a help and not a very helpful fellow, look at your car warranty info to find out if you have any tire warranty, if there is no mileage prorated warranty on the tire thru the tire maker just buy another tire like the other 3 and put it on the back

[kbahus]

What brand tires.........?

[BigHerm]

I had a sidewall puncture on my summer tires that were less than 10k miles old. Replaced the one tire only. Now the tires are close to 30k miles and they are all about the same (with 5k rotation front/rear). Never noticed any erratic driving behavior. 08 GTI

[Chainsaw_Willie]

You should always stick with the same brand and model of tire when replacing one for more reasons than just the fact the rolling diameter can differ between manufacturers and models.

Handling characteristics are also different and can really make the car handle weird and unpredictably if you're mixing and matching.

On a FWD car I wouldn't hesitate to replace just one rear tire unless there's a LOT of wear on the other one. Personally, I'd say up to 1/2 tread depth. This is on the rear. If there's a lot of tread depth difference then you will have issues with rotating the tires from then on as you don't want the mismatched tires on the front.

On the front I'd probably replace both if more than 3/32 wear. Whether the car has a limited slip differential would also play into my decision, and what kind of car. On my old beater Corolla with no limited slip that didn't handle worth a crap anyway, I'd probably replace just the one tire no matter what. On a nicer, better handling car that decision would be different.

Finally, as to the AWD all tires must be the same argument. Do some calculations and use some logic. When I hit a big rock buried under slush and destroyed one of the snow tires on my WRX I did the calulations and figured the difference between a new tire and the ones on the car would be like 5 revs per mile. At freeway speed I'm going a mile in just under a minute. Think about it. 5 revolutions in one minute. Try tracing a revolution in the air with your hand, and doing it 5 times in a minute (one every 12 seconds). If you really think that's going to generate huge amounts of heat and wear in a viscous coupling, well, you're wrong. Especially considering the couplings and differentials have to be designed to accept differences in speeds of the axles because every time you drive in something other than a perfectly straight line you're inducing rotational speed differences.

Saying 3/32 difference in tire diameter is going to destroy your differential or viscous coupling in an AWD system is like saying driving your car on lots of twisty roads will also destroy it.