I've got a set of snow tires on rims that have a total of maybe, oh 15,000 miles on them? Unfortunately, the front ones have uneven wear on them from an alignment problem that has since been fixed. My question is can I just replace the front two and leave the rear two as-is or do I have to replace all four? I seem to recall hearing that having tires with mismatched wear (and therefore slightly different circumferences) will put added wear on my AWD system.

 

Any ideas?

Bad idea, replace all of them, it will ruin your AWD if you dont.

If the circumference isn't within 1/4 inch, you have to get new ones.

 

Even if the circumference checks out to be close enough, its tough to say how a funky wear pattern will translate into the actual rolling circumference.

 

Now I'm a cheap bastard, I might mount 'em all up, find a big open parking lot, chalk mark all the tires, and roll it a few hundred feet and count the rotation of all the tires. That'd be the only way to be sure.

 

You could buy 2 new ones, and have them shaved down to the size of the un-funky ones. I hear there are places that will shave tires, but they'll only shave a tire that's never been used- as soon as it gets used, it picks up enough crud it'll ruin the shaving knives.

 

Maybe you can find someone with a front-wheel drive to buy your set?

 

Dave

I respect the opinions of others here, because they are saying the same thing Subaru says.

 

However I think the idea of replacing all tires when one goes bad is crazy. I replaced mine as needed until I had well over 100,000 miles before I ever heard this, so I just keep doing it and I put well over 300,000 miles on my Legacy Postal wagon before the transmission quit.

 

I am not telling you to do as I have because I may have just got lucky, But I will say with the amount of tires that I go through on my job it would be cheaper to replace the transmission ever four or five years instead of replacing all four tires evey time I ruin one tire because of having to drive on the edge of the road where so many tire hazards are. In fact I just picked up one new tire for it Monday. My last transmission lasted about nine years, with a full load of mail each day and all day of stop and go driving, and tires that were replaced as needed.

I also replace as needed. I wouldn't get all 4 unless there was significant tread depth difference.

 

Also you may find a used tire with similiar wear. It will be cheaper than a new tire also.

 

Look for a shop specializing in used tires.

I respect the opinions of others here, because they are saying the same thing Subaru says.

 

However I think the idea of replacing all tires when one goes bad is crazy. I replaced mine as needed until I had well over 100,000 miles before I ever heard this, so I just keep doing it and I put well over 300,000 miles on my Legacy Postal wagon before the transmission quit.

 

I am not telling you to do as I have because I may have just got lucky, But I will say with the amount of tires that I go through on my job it would be cheaper to replace the transmission ever four or five years instead of replacing all four tires evey time I ruin one tire because of having to drive on the edge of the road where so many tire hazards are. In fact I just picked up one new tire for it Monday. My last transmission lasted about nine years, with a full load of mail each day and all day of stop and go driving, and tires that were replaced as needed.

 

 

We need a USMB-mart of used tires so we can always find the right brand/model, with the right tread depth!

 

 

Dave

We need a USMB-mart of used tires so we can always find the right brand/model, with the right tread depth!

 

 

Dave

 

i have 2 205/75r15 TrailMarks that have about 7/32 on em.

 

FOR SALE! OR FOR FREE!! MY IN LAWS WANT THEM OUT OF THEIR GARAGE!!!

Have any of you who have run mismatched tires for long periods of time checked for torque bind? Torque bind shows that the AWD system is damaged. The way to check for it is to go into a paved parking lot and do the tightest circles and figure 8's you can. If there is a hopping, binding, a grinding noise or the car will not do it at idle (or near idle) then it has torque bind.

I had to replace my transmission at around 320,000 miles because of the torque bind.

Have any of you who have run mismatched tires for long periods of time checked for torque bind? Torque bind shows that the AWD system is damaged. The way to check for it is to go into a paved parking lot and do the tightest circles and figure 8's you can. If there is a hopping, binding, a grinding noise or the car will not do it at idle (or near idle) then it has torque bind.

We need a USMB-mart of used tires so we can always find the right brand/model, with the right tread depth!

 

Dave

 

That is an AWESOME idea! Everyone would need to post the circumference, not the tread depth, though.

I had to replace my transmission at around 320,000 miles because of the torque bind.

Am I the only one to catch the humor in this?

 

Steve

Sometimes the facts can have humor. Maybe if I would have kept the tires all matched the transmission would not have failed so early.

Am I the only one to catch the humor in this?

 

Steve

Sometimes the facts can have humor. Maybe if I would have kept the tires all matched the transmission would not have failed so early.

 

early

 

I'll be happy if the tranny in my 96 obs goes to 320k!

 

I did notice that the car has 2 different brands of tires on it. perelli on the front and continetals on the rear. Same size and they all appear to have roughly the same amount of tread.

 

With the argument that all 4 tires need to be exactly the same... at this point, I couldn't buy 2 new tires of the same brand and model (if I can even find them) because they'd be slightly larger due to the wear of my current tires.

 

I can't swing another $300 or so for 4 new tires so I guess I'll just run her with the 2 different brands of tires.

In theory, you could run them diagonal. One of each type on each axle. The difference side to side can be compensated for by the open differentials at each axle. Then overall, each axle would be rotating the same.

In theory, you could run them diagonal. One of each type on each axle. The difference side to side can be compensated for by the open differentials at each axle. Then overall, each axle would be rotating the same.

 

I will do that. Now each brand of tires are installed on the fronts and rears.

 

thanks

I think its absolutely crazy to replace all 4 tires. Now i agree they all need to be the same size, but shaving new tires makes me laugh. Thats such a brutal waste of money theres no way Subaru could endorse it.

 

I replace my tires in pairs: I wear the fronts down to 2mm real quick (bendy roads), then swap front to back and wear the new fronts down. Tires are then replaced as needed and it means i never have a bald tire on the front and a brand new set on the back.

 

If my trans lasts to 200k - thats fine in my book. The car will be long gone from me by then.

shaving down a new tire does seem prety neurotic and OCD! :-\

In theory, you could run them diagonal. One of each type on each axle. The difference side to side can be compensated for by the open differentials at each axle. Then overall, each axle would be rotating the same.

 

I completely agree with you, but I wonder if someone can answer this oddity I've noticed. When I have the car up on the lift and spin any tire, the diagonal tire is always the one to spin, not the one on the other side of the car. I'm not sure if this is congruent with what you've said or opposite.

 

I've got the 5mt on my '95 legacy.

How does tire pressure affect circumference? OCD? who as a subaru owner isn't ocd about tires and tire pressure-I check mine once a week at least. Mostly to make sure the rears are equal-the rear diff likes it that way.

 

Also, I'm thinking it is more important to have left and right tires being the same circ. than front to rear?

 

Also, I'm thinking it is more important to have left and right tires being the same circ. than front to rear?

 

Nope

 

At each axle, there is an open differential. On a 2wd car, you could have drastically different sizes and it would not hurt anything.

 

But the center has a Viscous Limited slip(MT) or a Hydraulic clutch pack(Auto).

 

Either way, the center wants the front and rears to spin at the same rate.

 

By running the 2 sets diagonally, overall you end up with each axle turning the same, a far a the center is concerned.

At each axle, there is an open differential. On a 2wd car, you could have drastically different sizes and it would not hurt anything.

 

Unless of course you have a rear LSD like me....

 

...and no FWD fuse so what the hell do i do when i get a flat!??!

Unless of course you have a rear LSD like me....

 

...and no FWD fuse so what the hell do i do when i get a flat!??!

 

 

Very good point about the LSD.

 

 

As far as getting a flat with you're car. 3 options:

 

1. Get a full size spare

 

2. Run you're donut on the front and don't drive far like that.

 

3. Fix it on the side of the road. (I carry a plug kit and a mini compresor) Fix a flat will work too, but then that tire is junk. But it'll get you home.

or put this in the tires before it happens

Slime! I havnt seen that in years. I used to run it in my ATV's tires. It saved my rump roast a couple of times.

 

I keep a can of that instant inflate stuff in the car because a flat tire out here can easily occur 100 miles from nowhere