Changing '08 RS6 Avant Wheels/Tires
-Don
Next, sure 20->19 will be an improvement w/r/t ride. Its fairly linear.
I did some quick math. Here are 4 sizes that are close in OD. The 255/40-19 size listed is frankly too small - 2% under size, resulting in rougher ride and possible rim damage. Bzzt to the originator of that.
Here are the numbers:
The last 4 numbers in each row are:
Diameter; % stock; Circumference; % stock
275 35 96.25 3.79 20 27.58 1.00 86.60 1.00
255 40 102.00 4.02 19 27.03 0.98 84.88 0.98
255 45 114.75 4.52 19 28.04 1.02 88.03 1.02
265 40 106.00 4.17 19 27.35 0.99 85.87 0.99
265 45 119.25 4.69 19 28.39 1.03 89.14 1.03
255/45-19 is 2% oversize and 265/45 is 3% oversize/. Both reasonable numbers. All my tires are about 2.5% oversize to better protect my rims from New Jersey potholes.
G





