So I uknowning was cruising around at 39psi (cold) in rears and 34 fronts since discount tire filled it that way for the day and I felt good the whole day and evena bit more quick around town in everything from acceleration to turns etc.

does tire pressure do this? I figure with low pressure it causes worse gas mileage meaning it must take more energy to lug a flatter tire that the opposite makes sense-question is if this is true and if so is this dangerous in anyway?

 

When I had my stock sport wheels I messed around with 42 all around and noticed some faster speeds especially 40 mph + , but the cornering sucked. I think the speed was better because of less tire to ground contact from the outter edge like 10 speed tires. I eventuall put them back to 36 front 40 rear .

 

Thanks man-I seriously was stunned when I just did a google search on a variety of terms and really came up with no answer-gosh I am in the medical field and you would be surprised how many docs are back in the computers googling diseases/treatments-and I cant even find tire pressure info! WTF! thanks again!

 

Just an update guys-ran 40 rears and 36 fronts for the rest of the day today and went for a highspeed cruise in the 110s or so and frequently do so therefore had a good comparison and noticed the following today
-quicker all around acceleration-ran some of my quickest 0-60 times today via g-meter, easier wheel spin and just overall lighter car feel
-MUCH better cornering-cornered a few hard times to test it out and just pulled me around the corner without any wheel hop which I would normally havea bit of
-and the most pleasent noticable difference was at speeds-well any speed but especially at 75-110 and over the car was more rock solid then ever. Even to the point where I could pretty much take my hands off the wheel ( i didnt but would loosen grip a lot) and the car just glided along.

I think anyone performance oriented which I assume a fair amount of you guys are-peak performance of the E60 is definetly in the 40 rear range and 36 fronts if not a tad higher-but for comfort of ride-definetly noticably "bumpier" and harder with more pressure-bmw likely sets 32/36 for balance of ride quality/performance but I really think performance suffers. And unless you are over 60 or have a baby to car around-even with the higher pressure the ride is pretty smooth-I mean not sure what someone wants. I was taking my mum around and she had no complaints.

Anyway HIGHLY recomend you guys try out the pressure-an easy mod for performance that is quickly reversed.

I am surprised each week at how much you can get out of your car if you try-with tweeking just the right things on the car it is a totally different machine.

 

Optimum tyre pressures are affected by a number of factors, not least construction and "size" (as you can see from the plaque on our cars, for example).

IHMO, without giving data about the tyres themselves, it is impossible to make judgements about pressures.

ABC