for the good year tires and maybe the contis

Technical info on the Pontiac Vibe and Toyota Matrix including do-it-yourself info
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coratz
Posts: 202
Joined: Thu Nov 07, 2002 8:32 am

for the good year tires and maybe the contis

Post by coratz »

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.
philndz
Posts: 791
Joined: Sun Aug 18, 2002 1:02 pm

Re: for the good year tires and maybe the contis (coratz)

Post by philndz »

HUH???
2003 Shadow Vibe Base 5spd - 53,000 MilesFlowmaster 60 series exhaust - Short Ram Intake SystemKonig Kaliber 17x7 Rims w/ 225-45-17 Kumho Ecsta 711's - Hotchkis Springs - Progress Rear anti-sway Bar My Vibe is FOR SALE: $8900
pmh013
Posts: 872
Joined: Fri Nov 01, 2002 12:25 pm

Re: for the good year tires and maybe the contis (coratz)

Post by pmh013 »

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.
2003 Satellite AWD Two Tone, traded off at 180,126 kmNow the (fourth) catalytic converter is someone else's problem Now driving a 2007 Dodge Grand Caravan
philndz
Posts: 791
Joined: Sun Aug 18, 2002 1:02 pm

Re: for the good year tires and maybe the contis (pmh013)

Post by philndz »

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
2003 Shadow Vibe Base 5spd - 53,000 MilesFlowmaster 60 series exhaust - Short Ram Intake SystemKonig Kaliber 17x7 Rims w/ 225-45-17 Kumho Ecsta 711's - Hotchkis Springs - Progress Rear anti-sway Bar My Vibe is FOR SALE: $8900
NovaResource
Posts: 2062
Joined: Mon Jul 08, 2002 12:22 am

Re: for the good year tires and maybe the contis (philndz)

Post by NovaResource »

The easy rule of thumb to remember is you loose 1-lb of pressure for every 10-degree (F) drop in temperature.
MadBill
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Joined: Thu Nov 14, 2002 9:39 am

Re: for the good year tires and maybe the contis (pmh013)

Post by MadBill »

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.
Lorin
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Joined: Tue Jan 21, 2003 11:31 am

Re: for the good year tires and maybe the contis (coratz)

Post by Lorin »

Coratz,You pressure swings look a little large. Did you remember to use an absolute temperature scale (Kelvin or Rankine)?
Lorin2003 Pontiac Vibe GT, Neptune-mono, moons & tunes, power package, side impact airbags, rear seat covers, bumper protector, cargo mat.Mods installed: TRD exhaust, TRD stb, Mods removed: TRD CAI - annoyed by CEL
coratz
Posts: 202
Joined: Thu Nov 07, 2002 8:32 am

Re: for the good year tires and maybe the contis (Lorin)

Post by coratz »

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