Why do the tires on my little used vehicle lose pressure?

February 1, 2004 7:47 PM

I've recently taken my truck out of active service and am only driving about once a week, often less. The tires always seem to be low when I do take it out. It's not the first time I've noticed an infrequently-used car losing tire pressure. Why does this happen? And what can I do to ensure that, if I put my car into long-term storage, it doesn't wind up with 4 complete flats?
posted by scarabic to travel & transportation (8 comments total)

And what can I do to ensure that, if I put my car into long-term storage, it doesn't wind up with 4 complete flats?

Take the wheels off and put the car up on jacks.
posted by kindall at 7:52 PM on February 1, 2004

Those who are storing vehicles and dont want to end up with flat spots on the tires, put the car/truck up on blocks or jackstands.

Storing vehicles for months on end usually means other preparations like changing the oil and removing the battery to place it on a trickle charger.
posted by gen at 7:52 PM on February 1, 2004

Fill the gas tank before you put it away for a long time, too.
posted by notsnot at 8:19 PM on February 1, 2004

Ok. Maybe "long term" is more than I mean. What would y'all recommend for storing something through a 2-3 week window? I cannot put my truck up on blocks because I might need it at any time, but then again, I might not need it for a couple of weeks. I guess perhaps I just need to keep a compressor neaby?

Also, I am really curious why this happens. When my car gets active use, the tires stay pressurized for months at a time, but 2 weeks of idleness seems to really deflate them. Any theories?
posted by scarabic at 8:34 PM on February 1, 2004

How do tires lose pressure?

Tires lose pressure naturally through the process of permeation. Changes in outdoor temperature can affect the rate at which tires lose air. This change is more pronounced in hot weather. Generally speaking, a tire will lose one or two pounds of air pressure per month in cool weather or even more in hot weather. Remember, underinflation is the leading cause of tire failure, so check inflation pressure regularly.
posted by mr_crash_davis at 8:40 PM on February 1, 2004

i can't see anything special about not using a vehicle that makes the tyres go down faster. you're probably noticing it more for two reasons - one, any gradual change is more pronounced over a long period and two, you're going to be more aware of problems when starting to drive again after a break.
posted by andrew cooke at 6:47 AM on February 2, 2004

This happened to my truck too. I couldn't make it stop happening, but I did find a solution to the "I don't want all my tires to go flat" problem. I got a small air compressor that plugs into the cigarette lighter that just stayed in the truck. I invested about 10-15 minutes of air pumping time before I drove it. They're cheap as hell [like $10-20 really] and can save a lot of heartache dealing with low possibly risky tires.
posted by jessamyn at 4:52 PM on February 2, 2004

I've heard of similar things happening with bikes, actually. I'm thinking, that if the tyres are sitting constantly in the same position, certain pores in the rubber are being stretched constantly and you make get more leakage through permeation, than if the tyre were being turned and all pores were instead being streched a little bit.
posted by Jimbob at 8:20 PM on February 2, 2004