Dear GSXR:

Thanks for your reply. I want to keep all tires the same so that I can rotate them. I would use 245/40's at all four corners but the O.E. spec for my car specify 45 series tires in the front and 40 series tires in the rear. Why does Benz specify a shorter tire on the rear axle than the front? They do this on all Benz's with the staggered wheel set up.

If I put 40 series tires up front would that adversely affect the increased shock absorbtion needed there because of the heavy V8?

I do have the MB GPS -- how do I use it to measure actual speed. I don't see a function on it that measures distance although I know it does measure distance to calculate ETA -- I of course can measure time.

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Marc
C55: Evosport headers & UDP's; AMS crank; TVT thermo; phenolic spacers; Denso IK16's; EuroTech ECU; RennTech cf airbox w/ Green filters; Z06 catch can; Sprintbooster; Optima RedTop; Quaife LSD; AMG: shift paddles, 030 rear calipers & rotors; Rotera brake lines; Euroteck CF lip; "C63" rear diffuser; 18" SLK AMG Turbines (summer); 18" OZ Superleggera's (winter); K40 dual f&r radar w/ laser jammers; MB: digital climate control, iPod kit & mp3 CD changer; iTronic B/T for MOST.