cbaber beat me to the obvious!
Quote:
Originally Posted by qx4dude
Also,
3) Assuming higher PSI = better FE, why do most auto makers choose a door sticker PSI number approximately 30% less of max sidewall pressure. If tires are designed to handle 200 PSI, wouldn't raising the pressure be the first place they go to help their cars achieve CAFE standards?
And don't say "it's a conspiracy".
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that's an abstract and 'simplton' question....you assume only one static situation.
getting better FE is not the function of the tire. Infact it is probably down the list.
the tire is designed primarily to make contact with the road, work as part of the suspension system (softening the ride) and have a reasonable wear rate.
adding more psi to increase FE will decrease the softness of the ride.
So from a human behavior point of view, if the car 'feels/ride' harsh ALL the time....it's hard to remember it's getting me 2 more mpgs. How many drivers really 'know' that 40psi is going to get better mpg? I just think the car rides like shxx.
But if I am highly concerned about mpg, I can live with the self induced pain of a harsher ride.
Pretty obvious really.
