Is it true that you need to change all 4 tires at the same time with an all-wheel drive car? I heard that if you don't you can mess up the differential or transmission. Is there any truth to this or is the tire guy trying to up sell me?

 

If you drive with 19's in the rear and 16's up front or to either side, then yes you can mess it up, but its impossible to have those kind of differences between new and used tires, so you would be just fine.

 

He is trying to take your money. With my PS2s, I use up 2 sets of rears for every set of fronts. There will be no problems from just changing one end of the car.

 

Tell me the brand of tire, and how much tread depth you have left on the front tires.

 

Thanks for everyones input. I didn't think it made a difference.

 

If the inflated measured diameter of the ones you intend to leave on are within a percent or 2 of the diameter of the new ones there will be no problem. Some say there can be up to 4% but I don't care to test that theory.