Have 2010 Challenger w/ Hemi, etc. Complete race suspension system bars, lowering springs (to level vehicle only), struts, chassis bracing, race shocks, and really big brakes!. Ride and handling on SCCA track and "twisty" rural back roads is phenomenonal and puts alot of "supercars' to shame. Original tires were Z rated "supercar" tires at 255/40/R20. They lasted about 15K (I abused them on purpose to test the suspension, etc...). Finally worn out... So research began... Will it fit the wheelwell? Will it fit the factory 9.5" rim with factory "offset", etc. Gotta be very very careful!! Arrived at 275/40/R20. Looked at everything; measured repeatedly, etc. Then to the types that met the specs.. Must be a XYZ type tire that can sustain 140-160 plus for limited periods of time.
The most cost effective tire that does all of these things is the Cooper. The others are "impressive", but usually as much as twice the cost, etc. Extremely well made; balancing was half the weight from the "others" (Rims are factory special rims and we did a balance check and they required almost NO balance); Tread is perfect for dry conditions and rain posed no problems. Tire Pressure is kept at rated 50 PSI; Lotta' theories on that; but you can run it down to 35-45, depending on what you are doing. Very "quiet" for this type of tire, but enough "noise" that matches the road surface. Durability? Don't know yet, but it appears that wear is consistent with pressure and what you are doing with the car. "Ride Comfort"? Very good considering that it is a harder compound. Sufficient feedback is there. After about 10-15 minutes, they are "hot and sticky" within reason, and cornering is really good, and very predictible.
Mid-range torque and power from performance motor/transmission can break any rear tire "loose". The RS3-S (at 275/40R/20...) is no exception. But.. it's very minimal; less than a split second and tires regain traction, etc.
Words of caution... Make sure it will fit your rim; fit inside wheel well, and does not exceed the max diameter specified for the car. Measure, measure and measure again! Use a reputable dealer who will order one, makes sure it fits, etc. You will not be disappointed!!
