Hi MBWorld, I would like to ask if it is possible to use 245/40 tires on the rear C63 wheels (9x18 ET54)? I believe the OEM Stock tire size for the rears are 255/35.

In addition, would there also be an issue of using 225/45 in the front wheels (8x18 ET45) vs the 235/40 OEM?

Will there be any problems for such set up? Any pros and cons of doing this?

It would be used on a 2009 Bone Stock C300 Sport.

I really have no idea on wheel set up, so forgive me for my ignorance.

Thank you so much for reading.

James

 

C63 original front & rear
235/40-18
255/35-18
on non-AMG w204 the front size is
225/40-18

For future inquiries...the recommended delta in tire size should not exceed +/- 2%

With that in mind you can use this online tool to do the math for you...
http://www.miata.net/garage/tirecalc.html

Comparing the original rear tire size to what you are asking you get a difference of 2.8%

If you are unsure about the pros & cons, I suggest you stick to stock tire sizes.