What makes tires lose pressure: time or miles?

[paulri]

Reason I'm asking, is that I just noticed that I'm driving my Civic a lot less than I used to, and I am wondering if I wait 2000 miles (a traditional way for me to gauge when to get them aired up), if that will be too long now---something like 4 months at the pace I'm driving at the last year.

So will a tire still lose pressure if the car sits? Or is it simply driving? Or both?

 

[bioburner]

Lots of factors. I had issues with tires(OEM Goodyears) on the Scion and changed out a pair and now they are not giving any issue at all in 7 months. Bad valves, tire bead leaks,poor rubber? I have had tires not give any issues for years and others on a regular basis.
Sure others will have some ideas

 

[paulri]

Originally Posted By: bioburner
Lots of factors.... Bad valves, tire bead leaks,poor rubber?


OK, although what I was talking about was not a problem with the tire/wheel setup, but just natural loss of air pressure--unless your point was that it is only problems like that, that would make a tire lose pressure at all?

 

[Rand]

Mostly time.

 

[heynow]

Originally Posted By: paulri

OK, although what I was talking about was not a problem with the tire/wheel setup, but just natural loss of air pressure--


Originally Posted By: paulri
I am wondering if I wait 2000 miles (a traditional way for me to gauge when to get them aired up)


Having to add air every 2,000 miles is not normal or "natural".
You have a leak(s) somewhere.

When using silicone grease on the tire/wheel contact surface, I have maintained the same pressure for years.

 

[Branson304]

I'm going to say time.

My tires with absolutely no leaks on all vehicles seem to lose about 1psi every 1-2 months & of course you see significant pressure changes when the temperature outside changes drastically.

I usually air my tires to 1-3 PSI cold above the manufacturer recommended then check them at least once a month when I check the oil & other fluid levels.

 

[bioburner]

I was trying to adress non tire mount issue. I have a tractor that has not had the tires touched since I bought it in 98. They will probably die of dry rot.

 

[gathermewool]

Originally Posted By: heynow
Originally Posted By: paulri

OK, although what I was talking about was not a problem with the tire/wheel setup, but just natural loss of air pressure--


Originally Posted By: paulri
I am wondering if I wait 2000 miles (a traditional way for me to gauge when to get them aired up)


Having to add air every 2,000 miles is not normal or "natural".
You have a leak(s) somewhere.


At what point do you pay money to have the tire removed and the leak fixed?

One of my tires consistently (never worse or better) loses a psig or two every month. I've soap-bubbled the valve stem and nothing. The others, I maybe have to add air once/year, usually when they're a few lower than I like when the temps dip down, and the TPMS light is on due to the one actual leaker.

I don't see any reason to fix this leak.

 

[nyumski]

time definitely

 

[heynow]

Originally Posted By: gathermewool
Originally Posted By: heynow
Originally Posted By: paulri

OK, although what I was talking about was not a problem with the tire/wheel setup, but just natural loss of air pressure--


Originally Posted By: paulri
I am wondering if I wait 2000 miles (a traditional way for me to gauge when to get them aired up)


Having to add air every 2,000 miles is not normal or "natural".
You have a leak(s) somewhere.


At what point do you pay money to have the tire removed and the leak fixed?

One of my tires consistently (never worse or better) loses a psig or two every month. I've soap-bubbled the valve stem and nothing. The others, I maybe have to add air once/year, usually when they're a few lower than I like when the temps dip down, and the TPMS light is on due to the one actual leaker.

I don't see any reason to fix this leak.


I don't see a reason either.

My point is that there is no "standard" time period to check tire pressure, or "normal" leakage rate. The reasons for loss of tire pressure and the rate at which it leaks vary so widely that there is no way to accurately recommend when to add air.

There might be a constant very small leak...
Or there might be an intermittent small leak that only releases air when that area of the tire comes into contact with the road while rotating.
There is no way for us to know.

paulri needs to monitor the pressure on a regular basis and draw his own conclusions, any recommendations from us are pure conjecture.

 

[bioburner]

If I have a tire-wheel giving greif I pull it, clean it well and drop it into the $5 kiddie pool and watch for bubbles. Aluminum wheels have lot of issues here in MN with salt, pot holes and cold extremes.

 

[CT8]

Holes and temperature.

 

[2009Edge]

Temperature has a big influence on tire pressure.

As Temp decreases so does tire pressure and vise versa.

See Boyles gas law.

 

[The motor guy]

I find vehicles that sit lose more pressure than a daily driver vehicle.

 

[mk378]

Leaks. That's always time-based unless you have something weird going on like the valve stem or the beads move and leak only when the car is moving. There is nothing about a normal tire that would make it lose more air because of driving a lot of miles.

 

[dblshock]

always have my tires mounted with bead glue.

 

[paulri]

Originally Posted By: heynow

Having to add air every 2,000 miles is not normal or "natural".
You have a leak(s) somewhere.


Just to be clear, the time I was 2 lbs under pressure, it was 10-11 weeks after the previous air up.

2000 miles has just been my normal time to swing by America's tire and have them air them up.

 

[paulri]

OK well it sounds like nobody is saying the more I drive, the more air I can expect to lose, so I'll just make a regular pressure check/air up for myself based on every x months.

Thanks everyone.

 

[otis24]

For every 10 degree drop in outside temperature, you lose one pound of tire pressure. I've heard it stated that filling the tires with nitrogen will negate that.

 

[supton]

I'd swear, bicycles of mine that get usage hold air better. Let them sit and they go flat. Probably not a good a/b comparison, but I suspect there is a factor there. Plus I think I've read Capriracer say that the waxes(?) compounds(?) in the tires do like being flexed in order to do their thing.