GenVibe - Community for Pontiac Vibe Enthusiasts

i did a lot of playing in my loads of free time. we all know how important tire preasure is for fuel economy, saftey,tire longetivity etc....toyota/pontiac recomends 32 psi front 32 psi rear this is how much it would fluctuate through the canadian seasons where i live if i did not not touch my tire preasure again.PSI TEMPERATURE22 -2824 -2026 -1228 -530 032 +834 +16 (ESTIMATED DATA)36 +32 (ESTIMATED DATA)i would recommend everyony buy a digital tire preasure gadge. you can all see the the flucuation as the temperature changes.

HUH???

What Coratz is saying (and correct me if I'm wrong), is that as the temperature drops, the air pressure inside your tire drops (because cold air is more dense, meaning it still has the same mass, just occupies a smaller volume). I would assume that the recommended pressure is based on a certain air temperature. I can see temperature around here fluctuate between -30 C and 0 C on the same day. Do I adjust for this 8 psi difference? No. Should I? Maybe.

quote:as the temperature drops, the air pressure inside your tire dropsthis i am aware of.....just a little confused w/ the layout of the post.....hehe its all good.....no need to explain

The easy rule of thumb to remember is you loose 1-lb of pressure for every 10-degree (F) drop in temperature.

quote:What Coratz is saying (and correct me if I'm wrong), is that as the temperature drops, the air pressure inside your tire drops (because cold air is more dense, meaning it still has the same mass, just occupies a smaller volume). I would assume that the recommended pressure is based on a certain air temperature. I can see temperature around here fluctuate between -30 C and 0 C on the same day. Do I adjust for this 8 psi difference? No. Should I? Maybe.A 30 degree change in one day has got to be pretty rare, but it does make sense to check the pressure more frequently when the temperature is changing and always maintain the specified values. (I cheat a bit in the Fall and go a couple of pounds high, knowing it will come down with the falling temperature.) This is also why you should check the pressures "cold", before you have done much driving and heated up the tires. By way of example, I drove a Corvette a couple of years ago which had the factory dash readout for tire pressures. Not only could you watch them go up for about the first 20 miles at highway speed, you could even see that the fronts, which were smaller and carrying a bit more load, went up a couple of ponds more than the rears! Some race cars use relief valves to keep the pressures from getting too high. This works fine until there's a long yellow, which cools the tires down and loses so much pressure that the handling goes off completely.

Coratz,You pressure swings look a little large. Did you remember to use an absolute temperature scale (Kelvin or Rankine)?

madbill you got it exactly!!!!!! thankyou very much for explaining the data. lorin - cold tire preasure readings.