Originally Posted by CarbonJoe

Todd, I've been running the P37 exclusively for quite a while. Recently, I've been having issues with the rear end getting loose. I have been running new sets of Sweeps I got at the Indoor Champs (multiple sets). I switched to a pair of 3 year old Jaco Blues I've had in a sealed tube and were never used. The car was 100% better, with zero setup changes.

In my opinion, something has definitely changed in the Sweep tires in the past year. At the beginning of the season I was running new sets I got at the 2011 Champs, and the rear was stable. New 2012 sets, the rear was loose.