I plan on doing a run on the 7th of June thru the mountains of Pa.With about 30 other BMW's and maybe some Ferraris' and Lambos' What pressure should I run in my tires..It will be mostly highway miles at speed of course..I'm running 245/40/18's on all four corners..I wish I went with M/pars so I could of went with the 275's in the rear..God I hate my wheels..

I keep mine at 40. Gauge at sea level shows 40 but when I go home which is at 1100ft it drops to 35. The higher you go it drops but not as significant. At 5400ft my tires show 30.