Infiniti recommends 18 psi below the max tire pressure?

[some_other_dave]

Originally Posted by TooMuchGlass

It definitely seems like using regular compressed air is preferable to pure nitrogen, but 40 psi is quickly becoming my absolute (and admittedly somewhat arbitrary) max.

First, if you are uncomfortable pumping your tires up above 40 PSI, then don't do it. Going higher will help your fuel economy, but if the idea bothers you then it isn't worthwhile. If you decide 40 is fine, try 45 after a while and see how you feel about it.

Second, nitrogen is fine in tires. The only way it is any better than air, though, is that it is more likely to be "dry". As mentioned earlier in this thread, most compressed air (that you can get at a gas station) has a pretty good amount of water in it. You don't want liquid water in the tires, and it will tend to accumulate a little more every time you add regular air.

Most of us don't add air repeatedly enough for it to be a real issue, unless the air supply you use is particularly wet.

The only real way that nitrogen is worse in tires than dry air is that it is more expensive. It's not worth it for most of us.

-soD

[Krayzie]

Originally Posted by Daox

Increased tire pressure will help prevent a blowout from bent rim or pinched tire from pot holes and bumpy roads.

About 2 years ago driving back to Toronto from NYC, just an hour out of the city i hit a pot hole doing about 130km/h. I Instantly started to feel wheel shake and knew something was wrong and started slowing down. Rim was bent and had to drive back 800km on my spare. I got lucky with no damage to the tire. BTW i was running 40ish PSI.

44PSI Max Sidewall
32PSI Honda Recommended

[niky]

I've bent rims at just 30-35 psi. You can bend a rim no matter what the pressure if your tire is low-pro enough.

[Krayzie]

just saying its easier to bend a rim with a lower pressure PSI, a higher pressure will give you more protection because the tire won't compress as easy

[undata]

Higher pressure makes the tire more likely to ride over something than sink onto it. Also, a good firm tire is better under wet conditions, because it can better channel water than hydroplane on the surface like a sloppy tire would. But I would never ever go over the max pressure listed on the sidewall. I just imagine hearing a tire design engineer's comments on the subject.

[metromizer]

Originally Posted by serialk11r

My car has 26psi front 32psi rear written on it, and factory suspension is not the most comfy thing ever, but after I increased the pressure slightly I think it's noticably less comfy.

I have an MR2 Spyder in my stable as well. What I found to be VERY important with many mid-engined cars, is the front-to-rear air pressure differential. If I run with 40psi both front and rear, the car is very 'squirrely' out on the highway. Lowering the front tire pressure to 34psi and leaving the rears set at 40psi cures that. BTW, for going around corners fast with performance tires, increased tire pressure reduces sidewall flex and is faster. Reduced tire pressures are only used on drag racing slicks for increased traction, not for cars that corner fast.

The tire store guys have it force-fed and beat into their heads to use the factory recommended tire pressures as a safety, um, liability reduction tactic. I guess auto repair stores have been successfully sued after a customer got into an accident, were under/over inflated tires have been mentioned as a contributing cause of an accident. Point being, don't bother asking the tire store to do it, you just re-set your own tire pressure after leaving the repair shop.

[niky]

Originally Posted by undata

Higher pressure makes the tire more likely to ride over something than sink onto it. Also, a good firm tire is better under wet conditions, because it can better channel water than hydroplane on the surface like a sloppy tire would. But I would never ever go over the max pressure listed on the sidewall. I just imagine hearing a tire design engineer's comments on the subject.

While higher pressure is good for preventing hydroplaning, it's because the opposite is true. A firmer tire sinks or cuts into the water better, which is why you want to pressure up to prevent hydroplaning.

LOWER pressures make tires more likely to ride over water puddles, causing hydroplaning. But this is also the reason we use lower pressures off road, to keep the tires from sinking more into the mud.

[slowmover]

Staying within the manufacturer specified pressure range and staying with a tire brand of at least the same quality as OEM equipped or better is the formula that works.

Otherwise, answer CapriRacers comments in full.

A few tenths doesn't pay for top quality tires should their life be reduced. The handling/braking/ride trade-offs have already been done.

Otherwise, show us where a percentage pressure increase -- contrasted to the full OEM range -- really works.

.

[some_other_dave]

What do you mean by "the full OEM range"? Do you mean the placard pressures recommended by the auto maker, or the "max pressure" reading on the side of the tire, or something else?

-soD

[ChazInMT]

To: Dave
6824 Under A Rock
Dirtville USA

Dave,

Slowmover is a huge believer in keeping your tire pressure at the door sticker pressure guide. Always has been, always will be.

FWIW.

You may go back to sleep now.

Charlie