When was the last time you checked your tire pressure?

Linas.P · April 7, 2018

Most of the time I check it twice a month and if needed refill once a month, but obviously look around visually before every drive. As it happened I been on holidays for several weeks and were driving very little, so the last time I had the pressure check was probably 6 weeks ago when temperature was still negative.

Last few weeks cars was riding quite harshly and I was thinking that I might need to inspect the suspension before MOT... anyway today I check the pressure when refueling and realised why.. I normally run higher pressure 38/40psi (instead of 35/38). When I checked the pressure today it was 42/44psi! So obviously weather got warmer, but I never though it could increase the pressure so much - I though it is max like -1psi.

J Henderson · April 7, 2018

Maybe once a month or so for myself. I always try and do it when the tyres are properly cold and use the airline that is less than a mile from my house, or place of work. Normally I will only put a couple of PSI in, if any.

Ala Larj · April 7, 2018

Every time I drive it. I use the tpms on the dash. It's in bars rather than PSI but can go up .2 of a bar between cold and warm weather.

The-Acre · April 7, 2018

10 minutes ago, Ala Larj said:

Every time I drive it. I use the tpms on the dash. It's in bars rather than PSI but can go up .2 of a bar between cold and warm weather.

Presumably checking on the dash came with later cars? Although mine has tpms I'm guessing it's there as a warning rather than a means of checking.

I've got a workshop at home so checking tyres is easy using my compressor.

NemesisUK · April 7, 2018

I check using the pressure display in the cluster every journey.

I recheck using a calibrated analogue dial gauge should the dash show a significant change (but not OOS) reading.

Usually the only time I have had to adjust the pressure is when the weather changes markedly i.e. Autumn and Spring.

MVrod · August 12, 2018

I do track days on my bike the tyre pressures have to be reduced by around 8psi frt and 10psi rear after checking after a few laps the increase is around 4-6 lbs psi it increases quite a way above possibly same with the cars in hot weather.

The-Acre · August 12, 2018

22 minutes ago, MVrod said:

I do track days on my bike the tyre pressures have to be reduced by around 8psi frt and 10psi rear after checking after a few laps the increase is around 4-6 lbs psi it increases quite a way above possibly same with the cars in hot weather.

After we did nearly 2.5k miles on our road trip in May I was sure the tyres would need inflating but they were exactly where they were when we left!👍

cidersteve · August 12, 2018

first time i have had tpms on a car and have relied on this really, however after 6 months thought i would check them , all ok .

Linas.P · August 12, 2018

1 hour ago, The-Acre said:

After we did nearly 2.5k miles on our road trip in May I was sure the tyres would need inflating but they were exactly where they were when we left!👍

Actually if tyres are all sealed properly etc. I would not expect to loose any pressure whilst driving even for 2500miles or more, I would expect to loose pressure whilst car is parked for prolonged periods of time.

August 12, 2018

You lose pressure through the rubber. Sealing obviously helps.

https://physics.stackexchange.com/questions/89962/how-does-air-escape-from-a-pneumatic-tire

Sent from my STV100-4 using Tapatalk

The-Acre · August 12, 2018

1 hour ago, Linas.P said:

Actually if tyres are all sealed properly etc. I would not expect to loose any pressure whilst driving even for 2500miles or more, I would expect to loose pressure whilst car is parked for prolonged periods of time.

I don't know anything about the science behind it all, I suppose I expected some kind of change due to high speed on the autobahns, snow on mountain roads and 30 degrees on city roads but I guess it goes to show my rims are sealing well. Actually that was May, and they still haven't needed inflating.

August 13, 2018

Pressure changes due to temperature, altitude etc, that's why you set them when 'cold'. Just driving along sedately will see a 0.3 bar rise from heat generated by sidewall flex.

Note cold pressure is your local cold pressure - ie if your climate is 37 degrees you will have less air molecules in your tyre 'cold' than someone in a 15 degree climate showing same gauge pressure. Remember when your gauge shows zero there is 14.7psi at sea level already - so correct term is gauge pressure rather than just pressure.

So when it's cold ie winter you check tyre pressure and it's down, not because you have a leak. The air has less energy and therefore pushing on the inside of the tyre less. So more air in winter to achieve same pressure as summer.