I have a 2001 Mercedes S430 and I currently have AMG rims on the vehicle.The AMG rims are staggered and I am considering making all 4 tires the same size. What should I be concern about if I make this change? The rear tires seem to wear out every three months and unfortunately I am not able to rotate them because the front tires are smaller than the rear. But if I change them to the same size for all 4 tires I can do more with them and perhaps they will last longer.

 

staggering is not the problem. The problem is you are buying high-performance racing tires.

 

Look at the "michelin pilot sport A-S" They have a treadwear rating of about 400. Compare that to what you have now. But don't go racing in them.