DrDiaboloco

I'm about to do an extended trip, and was thinking about running the pressures up a few psi over the "regular" pressure. I looked around here and on the web and can't seem to find much guidance on the pros/cons of this scheme. Pumping the heck out of your tires for few runs on an autocross is one thing, but I don't want to promote odd tire wear by overdoing it on a long trip.

Any reason to suspect I could do bad by running up the tires by, say, 3-5psi on the stock wheel/tire kit?

RotrDoc

Why do you want to do this? On the Interstates I drive, they're rough enough that I don't want a harder ride.

DrDiaboloco

Well I've heard/read anecdotal stories that higher tire pressures, within reason, increase fuel economy without undue wear. I don't know how accurate that is, thus the question.

It is well documented that running your tires with LOWER-than-recommended pressure degrades fuel economy noticeably, so the idea is that higher pressures would do the opposite. I have no doubt that it's true, but if the "cost" is uneven tire wear, I'll just stick with the recommended 32psi. I know you're supposed to run snow tires at a higher pressure (the reason for this is unclear to me, maybe because they won't heat up as much as normal tires and therefore the air inside won't expand enough?), so I wonder why one couldn't do it with "regular" tires.

Astral

Running at 34-36 psi (probably even 38) is OK. You get a slightly harsher ride, but better economy. How much better? Who knows, probably very small.

If you inflate extremely high (I bet more than 10psi), then you will risk wearing out the center faster than the sides.

So go ahead and inflate to 36psi. Rotate your tires regularly and keep her aligned.

(FWIW, I run 36psi with no problems.)

Astral

The reason you mentioned is why snow tires are recommended to run at higher pressure. Also, since snow tires are often mushy, pumping up the pressure helps get a little sharpness back into the steering.

DrDiaboloco

Thanks for the reply. I wasn't considering going as high as 10psi over anyway, just 4 or so to the 36psi you mentioned... Maybe I'll do it, maybe I won't. I'll make that decision at the gas station in the morning.

ZoomZoomH

iTrader: (1)

35psi is fine

SymSym

You should try putting 40psi. The higher the pressure the less sidewall flex you get. REpeated sidewall flex causes heat build up and this may cause a tire to fail. Remember that at highway speeds your tires will be a lot warmer that driving around town. You also get sharper steering response, but ride decreases slightly. NEarly everyone who tracks their cars raises the pressures to about 40psi.

Astral

Tires are designed to withstand street driving just fine at the stock pressure of 32psi. There is not enough heat buildup at 32psi to cause a tire to fail.

On the other hand, driving around with 28psi or 24psi, you're then causing excessive sidewall flexing and thus heat buildup.

SymSym

I am not suggesting that we should use 40 psi for general road use. However on the highway due to higher speeds the tires get a lot hotter than around the city. The tire will run a lot cooler if it is run at 40psi rather than 32psi, as there will be less sidewall flexing during driving. As such the risk of a blowout will be reduced, and as well fuel economy may improve slightly.