I myself stick to what the manual says. 31 front, 29 rear. I wouldn't even dream of putting 50 in those tires... my daily commute is bumpier than hell- lotsa construction that has made the rds very uneven, plus the combination of salt, ice, and stiff suspension would mean dangerous driving conditions for myself if I ran that much air in those tires. I like to keep em on the pavement... maybe a little more in better conditions, but for now I'll keep it where it is. I may be wrong, but I think I had a slip of paper issued by Dunlop that said something about running the tires to the car mfg's specs(which would make sense from a legal standpoint), but don't quote me!