: Tire replacement 2 or all 4

12-16-11, 06:53 PM
Long story short, I need to replace one tire. Tire place told me that I needed to replace 2 at a time or it could hurt my axle. I have an 07 sts4 which of course is awd and i read that certain awd cars need to replace all 4 tired at once or it will damage the car.

Any advice? I really can afford to replace 2 right now, anything I need to worry about?

12-16-11, 07:13 PM
I'd do all 4.

The AWD STS uses an open differential, so you'd probably be OK with 2 as long as you take care to match the size of the two tires you're keeping...

Many AWD car manufacturers advise owners to always replace the whole set. There are a few tire dealers that will wear a tire to match the other three; nice idea...

The OEM Michelins were pretty bad. What's on the car?

12-16-11, 07:43 PM
The oem michelins are on the car and they are the same size all around. Gonna replace the back 2 with michelin pilots I think. My tire that's bad is getting bought by michelin due to defect and the place I went had the pilots in stock. Just want to make sure I'm not going to damage my car by having different tires on front and rear.

12-16-11, 10:08 PM
Michelin calls most of their passenger tires 'Pilots'. Unless you spend a lot and buy the Sport or Sport A/S, you're getting a noisy tire with poor traction in adverse conditions. You can get a better tire cheaper.

12-17-11, 02:41 AM
After many moons as a Subie AWD owner, and replacing numerous sets of 4 tires I would suggest that you determine what percentage of variance in rolling circumference the center diff, or viscous coupling(?) in the AWD system will tolerate and operate from that base. Dealer, or reputable tire vendor should know, and be able to measure current tread depth and match things up, requiring only 2 replacements, if within tolerance. This is why tire rotation is so critical with AWD vehicles. I too would question continued use of the oem "MXM' "Pilot" tire, when there is much better rubber available (unless as noted Sport or Sport A/S models)


12-17-11, 10:49 AM
This depends on why you need the one tire.

If it's not worn out, then no, replacing just the one won't likely cause any problems.

CTBB got it. Measure first, then decide.

I've done 5-tire rotations on my wife's AWD RX300, and there hasn't ever been a problem. Obviously, one tire will always have more more tread than the other three...the one which was riding along as the spare.

12-17-11, 10:54 AM
Don't know where you are at....but in my town we have several used tire dealers. I was in the same position as you about 15 years ago, got one tire which wore down, he had an exact match. How do they get used tires? They tell me there are folks who buy brand new cars and say I don't want such and such a brand and pull off perfectly good tires. I think I paid maybe $10 MOUNTED......