I suppose the optimum tire pressures would be both subjective and objective. Play around with each combination for at least a couple of months then make the decision for a prolongued period. Taking for granted that the oil overfill problem is taken care of pretty well leaves comfort/control/tire wear and mpg. We've made our decision on 42 front/ 40 rear. Perhaps an infinitesimal more bump than lower pressures but thats to be expected.... still a very comfortable ride. Control "seemed" somewhat improved. Tire wear will have to be determined after the prolonged test period and then only by comparison with someone who has used a different pressure over roughly the same test period. My MPG comparison over 4 tankfills during relatively same temperature and road conditions are: Tank #15 46.65mpg US Tank #16 44.86mpg US Upped tire pressure from 35 front/ 33 rear to 42 front/ 40 rear Tank #17 47.46mpg US Tank #18 53.61mpg US Vehicle total mileage 6974.5 and just over 1 year in operation. I'll stick with this until my data tells me differently. Heck,our darling isn't even broken in yet.