Mystery Inflation...

[Wiscon_Mark]

I hadn't checked my tires (Michelin Xones) for a couple of months, so I decided to check the inflation and the left drivers side tire was at 38 psi! It's supposed to be 30 (cold psi) (I hadn't driven it all day) and i know I filled it up to specificiations before...how did it gain air? All the rest were fine....

Also, would this have had a noticable effect on my mileage?

[gator gt]

easy there my friend.

remember, always take into account the current temp when you take the reading. for every 10 degrees your pressure will on average change 1 psi.

try adjusting your pressure in the morning (early & before you can get any significat heat into the tires) and that should be your 'cold' pressure. If you measured the tires after 3-4 hours of sitting in the sun (regardless if driven or not) they will be warmer and pressure will rise. They are black after all and a magnet for heat.

example: you fill or adjust the tire pressure at 45 degrees F in the winter. Temp drops to 15 deg at night....you lost ~3 psi.

inversly, you fill the tires at 630 am in the summer, temp will be around 50 deg F, at 1 pm its now 95, your pressure is now ~4.5 psi above your cold pressure, on average.

So, ladies and gents, take into account the time of day, how long the car has sat in the sun, if you've just come back from a spirited run (like I did today :twisted: ) or if its fricken freezing out and it looks like your tires have been slashed.

as for your automatic inflation system...where did you get it? j/k. does that tire get sun and the others don't?

GGT

[Wiscon_Mark]

actually, that tire was the one farthest away from the sun....maybe all the others were a little deflated and that one just held pressure or something and it looked super high...w/e it is, I will make the corrections when I get up tommorrow morning to get the paper....thanks gator!

[shazapple]

Did you use the same pressure gauge? Youd be surprised how much they can vary

[Wiscon_Mark]

Yeah, I did....

[blackgtbeauty]

have any garden gnomes on you lawn? maybe a air comp laying around? hmmmm

[gator gt]

no, no, no, its not the Garden Gnomes you need to watch out for, its the Ghetto Gnomes....they're the tricky ones! Talk about pests!

Any resolution to this one, Mark?

GGT

[Wiscon_Mark]

The rabbits were messing with the compressor!

No, nothing about how it got so high, but my tires are holding steady at the correct pressures, so I'm not terribly worried.

[Sarra]

Barometer? Maybe it was ultra low, did you happen to fill that tire with air during a hurricane? While in the eye of it?