I bought my 03 about 7 months ago, and it had 205/55/16's in the front and 225/50/16's in the back (Fuzion ZRIs). Well after reading all the tire threads regarding the non OEM sizings, I replaced my rear tires (because they were almost bald) with 245/45/16's in the same tire. I did this last week, and I have noticed that the rear end feels extremely unstable.

At high speeds the back end seems like it is pulling all over the place. I went through some local mountain backroads and through the twisties the rear end didn't feel stable. The back end didn't get squirlly, or loose, but it didn't feel planted.

I set the tire pressures on the front and back to 32lbs right after I had the tires mounted, since I never trust those tire guys.

Any ideas, as to why the new tires are acting the way they are? I am hoping it's just because of the tires being new, and they need to be broken in. The original tires were very stable.

Thanks for any advice / suggestions.

 

Well beside the fact that if you put "fuzions" on the rears, you wont have the same grip as SO-2's. New tires have a release compound coating so the will come out of the mould. This takes a few miles to wear off. So slow down, or just take to a big parking lot do spin donuts for a while

 

break them in and check alignment

 

New tires will be much more squirmy. Tread blocks are free to move around a lot more than on nearly bald old tires.

One of many factors that's way more important than 225/50 size vs. 245/45...

 

Also, wider tires will feel like they are following ruts and grooves in the road more.