QUOTE(orthobiz @ May 17 2008, 08:28 PM)
This is a GREAT question. And I don't know the answer. I usually inflate tires to about 2-4 pounds below the maximum allowed on the actual tire. I've never gone by the manufacturer's recommendations. But a friend recently insisted that the auto manufacturer knows better for the specific car.
I always thought a higher pressure was better for mileage, wear and even performance.
Someone settle this, please!
Paul
Close-to maximum pressure is OK, if your 914 is loaded (no, not from drinking too many Pina Coladas). But under normal driving conditions, overinflation reduces the tread contact patch on the pavement, so handling will be compromised to some extent. In essence, you're riding on only a portion of the contact patch because you've stretched the tire with high pressures. Yes, increasing the pressure will increase fuel mileage, but you'll also have a harsher ride. But contemporary tires are designed to have pressure that will be most beneficial for your specific driving needs. The important thing for non-competitive driving is to keep the contact patch (all of it) on the pavement. Overinflating will "round" the patch, thus not putting all of it on the pavement.
My suggestion (and this is only mine) is to follow the manufacurer specs, for your tire and car - for normal driving. Competitive driving can change all of this.
Pat