Time for tires -- 20" fore and aft

[j_beede]

MY05 C2 is lowered via TechArt and has 20" OZ superleggara all the way around. 12" in the rear and 8" in front (I think). Rim width is not stamped anywhere I can see.

 

My ancient Goodyear F1 are sized 295/30-20 rear and 245/30-20 in front. As expected the fronts have near zero wear while the rears are gone. I actually like the performance of the GY F1 and would have been happy to match a new set of rears with my existing healthy fronts. My tire dealer says no new F1 rears to be had.

 

Question: How are tires sized for aftermarket rims? The tire dealer seemed to think I should have 255/35-20 in front. With a staggered setup is there some sort of guide line?

 

FYI: Not many choices in my current tire sizes -- Pilot Sport ($340-380) or PZero ($400+)

...j

[jl-c]

                                Circumference in inches

79.95 front stock

82.22 rear stock

84.63 front yours

80.93 rear yours

You do the math!

ABS, Traction, Speedo issues…………

[j_beede]

jl-c,

What assumptions did you make wrt stock tire model and size? I suspect there is a wee bit of difference between the standard 18" and optional 19" sizes for MY05. I would expect differences from brand to brand within a particular size.

 

My GPS and speedometer are in "lock step" with my 295/30x20 and 245/30x20 setup. Anyone know if speedo calibration is available via Durametric? Per jl-c's circumference numbers I would expect to see a GPS v speedo delta.

 

If I go to a 305/30-20 rear I think there are a few more options for me. Anyone ever run PZero Corsa for use on a street car?

 

 

I didn't think so.

[j_beede]

                                Circumference in inches

79.95 front stock

82.22 rear stock

84.63 front yours

80.93 rear yours

You do the math!

ABS, Traction, Speedo issues…………

 

                                Circumference in inches

79.95 front stock

82.22 rear stock

84.63 front yours

80.93 rear yours

You do the math!

ABS, Traction, Speedo issues…………

 

Thanks for the numbers jl-c. If these numbers are spot on they give me the 0.75" lift in front that I need to compensate for the inch I lost with the TechArt spring lowering kit. The front of my car is plenty low--looks cool but I wouldn't want to go any lower.

...j