brianh

I while ago I posted pics of my rear tire with a screw embedded. The position of the screw made the tire unrepairable and I wound up buying two replacement tires. In the front I have Michelin XGTV - probably about 2/3 worn and in the rear two new Michelin XGTV4 Pilots. One thing... the tread pattern between old & new (front & rear) is significantly different.

With the new tires in the rear I can feel a side-to-side jiggle at the back end, more pronounced at higher speed. I don't remember the car ever doing this before. I figured to begin with it was just something to do with breaking in the tires and it would go away - or I wouldn't notice it after a while. However, after over 1K miles it's still there.

Does anyone know what may be causing this? Could the different tread pattern between fronts & rears be doing this? - It's hard to imagine this being the case - but I'll bow to greater experience. Is it possible that improper balancing could be the culprit?

Any thoughts would be appreciated...

brianh

'94 968 (31K miles)

brownd911

Brian, there are two things to consider, first is the tread design itself and the difference in patterns can cause a different feel in the handling characteristic in the vehicle. Second is the difference in tread depth and as you say your worn tires are 2/3 gone and the new are, well new with a new tread depth of 10/32 with more maleable tread blocks, the tires at the opposite end have a shallower tread depth thus more stable tread blocks - giving you a different feel - which I'll offer to translate as quicker response on turn-in. As an asside, the best place for the new tires is on the rear - as understeer is easier and safer for most of us to handle. You have a choice to make, either live with the 'condition' or replace the fronts with matching tires.