xsta_c

On an 2004 S430 with the amg sport package, what is the standard tire size for the front and rear with the AMG rims?

Thanks

newton22

18s staggered right?

Off the top of my head: (F) 245/45ZR18 (R) 265/40ZR18

kenstudios

Thats right. Look on the driver side door panel for the recomended tire size.

xsta_c

thanks guys.

What would happen if I put 245/45/18 on the front and 255/35/18 on the rear. would that cause a speed sensor malfunction and affect my abs or esp?

newton22

255/35 sidewalls are too small compared to front. You can do that if you want to, no malfunctions (No sensors to test tire size, don't even know if that's possible lol).

vraa

Is there a reason that you can't do 265/40 in the rear?

The overall rolling diameter is determined by the thickness of the sidewall. The thickness of the sidewall is determined by the aspect ratio compared to the width of the tire.

The first number is the width in milimeters of the tire. The second number is the percentage of that number that becomes the sidewall. The third number is the diameter of the wheel.

Seeing how you are running 18" wheels in both situations, we can take that constant out of the equation.

We only end up with two things then, the sidewall height of OEM spec, and sidewall height of your spec.

OEM height = 265*.40 = 106
Your height = 255*.35 = 89.25

So you're off about about 2 centimeters and IMO that's a pretty significant difference. I suck at percentages, so I'll do it both ways.

17 / 89 = 20%
17 / 109 = 15%

Average those two, and we get a 17% error. That IMO is a significant enough difference. Now if you were doing 255/45 (for example) you might be a little better, but the point is to compensate your skinnier tires, but having a larger aspect ratio.

I'm sure I've messed up some math some where, I'm on winter break...