C63S Coupe dropping from 19/20 to 19s for track
Thread Starter
Senior Member
Joined: Dec 2010
Posts: 306
Likes: 27
From: Earth
C63S, 2004 S4, 2001 S4 Avant
C63S Coupe dropping from 19/20 to 19s for track
Have an odd question about tire sizes and likely am overthinking it.
My Michelin P4S are done and so now am looking at a set of tires and wheels more aimed for track use and planning to drop from 19/20 to 19s. As a result I am trying to figure out the optimal rear tire size, since the C63S coupe comes with either 285/30-19 or 285/30-20 in the rear (25.7" vs 26.7" diameter, about 3.7% difference). Basically, is the vehicle calibrated to the 19 or 20 inch wheel and will going bigger diameter than the OEM 20" setup mess thing up for track use? For example, would going to 295/35-19 at 27.1" diameter (like Cup2) start to mess things up? Or would the ideal diameter be between the two OEM sizes, like a 305/30-19 (Supercar 3)?
My Michelin P4S are done and so now am looking at a set of tires and wheels more aimed for track use and planning to drop from 19/20 to 19s. As a result I am trying to figure out the optimal rear tire size, since the C63S coupe comes with either 285/30-19 or 285/30-20 in the rear (25.7" vs 26.7" diameter, about 3.7% difference). Basically, is the vehicle calibrated to the 19 or 20 inch wheel and will going bigger diameter than the OEM 20" setup mess thing up for track use? For example, would going to 295/35-19 at 27.1" diameter (like Cup2) start to mess things up? Or would the ideal diameter be between the two OEM sizes, like a 305/30-19 (Supercar 3)?
