[eco30BMW]

I really didn't realize this was such a touchy subject, or that argument had been going on elsewhere on the board. I'll keep it civil, but I do have a few responses.

Originally Posted by Daox

Maintaining momentum through turns is a good idea for saving gas. I see no reason to take that tip it down.

Agreed, my point is that people will take turns faster than they ought to if they believe they have more grip than they really do.

Originally Posted by Clev

Taking the above to its logical conclusion, inflating tires higher than placard makes the contact patch even a bit smaller, which would not increase stopping distances.

Oh, ok, so taking that to its logical conclusion, having NO rubber on the road would not increase stopping distance, correct? The resource you cited was written during the Firestone fiasco, where the concern was underinflation. It's clearly only comparing underinflated tires to ones inflated to the placard pressure. You're applying a trend across a boundary (the placard pressure) and it's invalid.

Originally Posted by Weather Spotter

Last winter I did some tests on my weekly drives home from school. Higher pressures increases my wet and snow traction by a good margin (over 15% better traction). I also tested stopping distance on wet and icy roads. I found that higher PSI was about the same to slightly better stopping distances.

I'd really like to hear how you arrived at that figure, because since opening this thread I have searched for a good study with a skidpad or drag strip and different tire pressures and found none.

Originally Posted by Weather Spotter

When I worked at a major auto maker I liked to put this topic up for discussion. The people who did track testing and noise testing came up with the same resign for the OEM specks on tire pressure: ride comfort and noise.

Had you asked the people who design the suspensions I'm sure you would have gotten a different response. The tires act as a spring, and are designed into the suspension that way. You're also messing with the dynamic geometry of the tire while cornering, and I'm sure there's suspension designers that would not be pleased with that.

Originally Posted by Vegas Dude

Lastly, over-inflated tires will make it easier to spin your tires on dry pavement. So while it's easier to do a burnout, your 0-60 and 1/4 mile times will increase. Also not really much of a problem for us non-racers and ricers.

But that's one more vote for less traction.

The bottom line is that EM is responsible for what it puts on the site as fact and there is no proof that increasing tire pressure past the placard spec will increase traction. Just take it down already. I don't understand why EM would feel the need to say anything about wet traction anyway, many people here seem to feel it's a question better left to performance driving forums.