Does a tyre go flat if car is unused for ages?

This Honda Civic was left parked in this spot for a period of six months, untouched and unused during the entire time. Upon returning to the car, it was found that one of the tyres deflated:

http://img222.imageshack.us/img222/4...46smallxx0.jpg

Pumping it back up made it good as new again.

I also have a Honda Civic Coupe which does not get used during the working week at all and perhaps only gets used once or twice on weekends. Yep, it's a very low use car. However, over a period of several months, I notice that the tyres also gradually deflate. I usually keep them close to 40psi but after a while all tyres are at low 30s psi...

On the other hand, my wife's car gets used every single day of the week, and even more on weekends. And its tyres always remain pressured up constantly and never seem to deflate even slightly whenever I check them.

So.......

It seems that a low usage car (or 100% unused) that has the tyres sitting stationary for long periods of time will gradually deflate, but a tyre that gets used every day seems to keep its inflation up? Anyone else noticed this?

If you blow up a balloon eventually the air seeps out and it deflates. Tyres are no different. Some tyres will deflate slower than others - there is no magic to it.

But then why does my wife's car - a CR-V which gets used alot every day - never needs its tyres topped up even after months of not checking it? Is there a correlation between tyres which get used every day and tyres that don't in regards to holding pressure and the rate at which it deflates?

Quote:

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Originally Posted by Alpine

But then why does my wife's car - a CR-V which gets used alot every day - never needs its tyres topped up even after months of not checking it? Is there a correlation between tyres which get used every day and tyres that don't in regards to holding pressure and the rate at which it deflates?

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Tyres can get very slow leaks through the valves (or if not mounted perfectly between the rim and the tyre) so it really just depends car to car. It also depends on the age of the tyre. With the CRV I imagine you also have quite a bit of rubber so it might take longer for air molecules to get through the rubber. Just a theory...

Yeah, I've noticed that too, Alpine, not that it really bothered me. If you're not going to be using the car for extended periods it is recommended that the car be lifted off the ground to take the weight off the tyres and let the suspension relax. If left stationary for long periods the tyres can develop flat spots. Good to hear that you do check your tyre pressures on a regular basis though :thumbsup:

how about 1 and a half ton on you body on see how you go, hehe,

but be carful, i did the same thing once and the tire blew up just after i pumped it up again, you could see cracks on the side, if u dont see cracks it should be fine

i reakon some bored guy deflated it to piss u off =D

Thats a good question. you hold a valid point never thoguth about it before but that happens with the car we have that never gets used.

it depends on the tyre you see..
as u said only 1 out of the 4 tyres in the car was deflated..

meaning the other 3 were fine..

so you probably have a little leak sumwhere on the tyre dat deflated..

yup with time air leaks out. Also tyre age is a deciding factor ~ and also if the tyre has been used before hand etc

As has sort of been mentioned, I would also guess it depends on how good the original seat was when they mounted the tyre.

That being said, I do wonder how well things like nitrogen filled tyres last and if it would seep out differently.