I hope I am posting this in the right area. My question is about raising tire pressures to the max limit stamped on the tire. I see in most "hypermiling" articles that this is recommended to increase mileage, does not cause excess wear of the tires and that the harsher ride is soon gotten used to. Here's my question: if this is such a "free lunch", why don't the auto makers do this? They are struggling and competing for every 10th of a mile per gallon. Why would they ignore such low lying fruit on this amazingly tough issue? Maybe this is not REALLY safe, after all????