Definitions by patred

OPR 

Other People's Rubber. A term autocrossers use to describe tire rubber that has worn off racing tires, usually building up in piles off the proper racing line. A hindrance to tire grip, OPR can be dragged on course by competitors during their course walks causing Porsches Caymans to be reduced to stock Miata speeds.

I would have gone faster on that run, but my tires lost grip in the slalom because somebody spun before me and dragged some OPR on course.

I had a 2.5" wide continuous line of OPR on my front tires, removing my effective contact patch by over 60mm, or making my tires effectively 205 instead of 285.

OPR by patred August 11, 2011