Tire Size Difference a problem?!?!
 

So the wife managed to pickup not one, not two, but THREE screws in the left rear tires this week. Not sure what construction site she was racing through, but she found a good one. Took it into the local tire shop this morning, and they could've patched two of the holes, but the third one was too close to the sidewall to repair, requiring a new tire. The tire in question is the left rear. We had considered replacing both rear tires, but the other 3 still have over 80% tread left, and I don't really want to drop any extra cash on the car at the moment than I have to.

So now we have a brand new Hancook 225/45/18 on the left rear, and a gently used 225/45/18 General on the right rear. I didn't even consider the idea that the slightly worn tire would be a slightly different diameter than the brand new one until I was merging onto the expressway on the way home. I ran it up through 1st, 2nd, and partially through 3rd to merge in. On each shift it felt like the front end "fell" to the right, and the acceleration of the next gear "lifted" the front to the left. There was a slight pull in the wheel as well that has not been there before under heavy acceleration. I'm certain this is due to the new tire being slightly larger than the old one on the other side.

The biggest concern is the rear differential at this point. Am I going to tear up any of the internal components running the tires this way? Should I go back and have them swapped over so that the two "best" tires are on the front of the car? Will that effect the handling poorly as well? Should I just bite the bullet and drop another $160 on another rear tire, and keep the old one as a "spare" for the next time she runs over a pile of screws?!?!

Any help would be greatly appreciated.

Anyone? Surely this has been encountered before. Search isn't being very helpful at this point either ......

You'll be fine as is, considering 80% tread on the other three coners. New tires take about 500 miles to break-in properly and therafter you shouldn't notice the effect.

Ideally they'd be matching makes on the same axle, but if money is tight again you'll be fine.

Thanks for the info. I drove it again last night after she's been driving it since Saturday. It still pulls HARD to the left under power. SO much so that it requires input from the steering wheel to keep it in the lane between shifts!!

I'm going to get an appointment setup to get another tire on the rear to match. I don't really want to spend the $160 on it right before vacation, but it's gotta happen since she'll be meeting me in Philly with the RX8. I don't want her dealing with that for a 10hr drive!

I'd recommend rotating the mis-matched rear tires to the front, and the fronts to the rear, if you aren't going to get a match for the other rear tire. The impact on the front will be much less noticable.

Getting a new tire to match is the right thing to do though.