Excessive rear tire tread wear on AWD

I have a 2004 Subaru Forrester with 95,000 miles on it. This past winter I switched to Nokian all weather tires to get me through the upstate NY winter (they were awesome). I was dissappointed to notice that the rear tires wore a great deal, and significantly more than the front. My mechanic is scratching his head and I don’t want to go to the dealers who have proven to me that they will find some way to charge me $500 to not fix this. I had Coopers mounted this week, and I’m worried this will happen again.



Has anyone else experienced this phenomenon?

Did your mechanic check the wheel alignment? When was the last time that you had a 4-wheel alignment done on the vehicle? Are you sure that the tire pressure in the rear tires was set correctly? Was the tread wear “even” across the tread, or was it more excessive on the inner or outer edges?

If I am correct that your rear alignment is “off”, then your Coopers will soon start showing excess wear in the rear also. Have the alignment checked as soon as it is convenient, and of course, check your tire pressure every couple of weeks.

Have a four alignment performed. Also during this period how many miles travelled? You should be rotating 7500 miles/manual but I use every other oil change, about 8-10k on my 2005 Subaru Legacy wagon. I do not notice any more wear front to back.

Thanks for the quick reply. I’ll admit, I’m terrible about rotating my tires, but I do get them aligned whenever I get new tires or it feels out of alignment. The odd thing about this is, it has never happened before with this car, and the wear is even on both tires, in the middle of the tire. These were new as of last November, and I probably put 8-10,000 miles on the tires. I guess I’ll try the tire pressure and alignment, but I never really kept up with that before and didn’t have these problems. Thanks again for your response.

Thanks for the quick reply. I’ll admit, I’m terrible about rotating my tires, but I do get them aligned whenever I get new tires or it feels out of alignment. The odd thing about this is, it has never happened before with this car, and the wear is even on both tires, in the middle of the tire. These were new as of last November, and I probably put 8-10,000 miles on the tires. I guess I’ll try the tire pressure and alignment, but I never really kept up with that before and didn’t have these problems. Thanks again for your response.

If the tread wear is taking place in the middle of the tread on both rear tires, that is a very strong indication that the inflation pressure in those tires is too high. (Wear on the edges indicates pressure that is too low, and wear in the center of the tread indicates pressure that is too high)

Check the placard on the door jamb. If the Forester is like the Outback, it will specify lower pressure in the rear, as compared to the front. On my Outback, it calls for 30 front/29 rear. In the interests of better handling and slightly better gas mileage, I run my car with 32 front/31 rear, using the same front/rear bias of 1 lb. My guess is that your rear tires were consistently inflated by at least 8 lbs. over the recommended pressure.

Hopefully you are not one of those confused people who use the inflation pressure listed on the tire sidewall, rather than the correct pressures listed on the driver’s door jamb. If you have been using the inflation pressure listed on the tire sidewall, then your tires have been GROSSLY overinflated. Using the tire pressure listed on the driver’s door jamb as your guide, you can safely go a few (2, 3, 4) lbs. higher, but if you use the pressures listed on the tire sidewall, you could be inflating your tires by–perhaps 15 lbs, and that would definitely lead to excess wear in the center of the tread, as well as dangerous handling characteristics in the event of an avoidance maneuver.

Incidentally, by being “terrible” (your words, not mine) about tire rotation, you are also inducing excess wear on the vehicle’s center differential, due to major differences in tread depth from the front tires to the rear tires. I really think that you have to begin to pay much more attention to basic maintenance–which includes tire rotation on a regular basis, as well as maintaining consistent tire pressure that is in conformance with the car manufacturer’s specifications. Failure to pay attention to these things inevitably winds up costing you A LOT of money, whether it is for new tires, a new center differential, or…

You need to rotate your tires more often. You may have NOT had a problem in the past, but that doesn’t mean you CAN’t have a problem. Rotate the tires more often…get a 4-WHEEL alignment from a reputable shop (NOT MIDAS OR JIFFY LUBE OR EVEN A NATIONAL TIRE COMPANY).

I see the light. I’m sure my tires have been overinflated. I can actually blame my husband for this, he does this on our cars and even on our bikes. He actually had a blowout on his relatively new tires (Subaru Forrester also) for no apparent reason. I vow to take better care of my tires from now on. Thanks for your help.