Tyre pressure: what does this mean?

[Rapido925M]

From an article on GB News (!):

Changes in temperature can cause pressure to contract, meaning air is typically lost at a quicker rate over winter.

MSN

I think it should read: Reductions in temperature causes air to contract, resulting in a reduction in pressure.

I think it should then continue: meaning air is typically lost at a slower rate over winter.

What do you think?
(Other than don't believe anything you read on GB News )

 

[CAB96]

I think they probably AI generate their articles.

I would think they are trying to say that the normal reduction in pressure over time will be exacerbated in cold weather.

 

[Reallyretired]

The low pressure warning on my mini came on with the first frosty day. Tyre pressures are usually stated that they are at 20C and there are tables on the Internet to show the adjustment you should make for other temperatures.
Nothing to do with loss of air, typical of the illiterate journalism we are afflicted with these days can't spell, don't understand grammar and are totally uninterested in factual accuracy.

 

[poppycamper]

The low pressure warning on my mini came on with the first frosty day. Tyre pressures are usually stated that they are at 20C and there are tables on the Internet to show the adjustment you should make for other temperatures.
Nothing to do with loss of air, typical of the illiterate journalism we are afflicted with these days can't spell, don't understand grammar and are totally uninterested in factual accuracy.

Anyone who does not have tyre pressure monitors will be amazed, as I was how much tyre pressure changes with temperature..
Even in summer and you leave with recommended tyre pressure, once travelling that pressure can increase by circa 10 psi..
My tyres are at recommended pressure and in winter temps as we are having now, my tyrepal will alarm,, but very shortly will come back up to operating range.. Yes I could adjust minimun alarm value but it is only in severe cold conditions that they alarm..

 

[Daffy64]

Tyres will naturally lose a very small amount of pressure over time but I think the article means that in colder temperatures the pressures will drop due to the cold - they also increase when the tyres warm up.

A decent TPMS will compensate for temperature but the best way is just to set them cold to the recommended pressure and then check/adjust them every so often.

We did a big project on Truck tyre life some years ago which involved taking pressure readings and adjusting pressures every 6 weeks, basically between January and July we were letting air out and from August to Dec we were putting air in.

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[poppycamper]

Tyres will naturally lose a very small amount of pressure over time

How much.. and over how long..
I do not have to put any air in my tyres both on my moho ( steel rims ) or Mrs Poppycampers car ( alloys ) from one MOT to the next... and before you ask.. Yes .pressures are checked every 2 weeks..

 

[Carpmart]

Tyre pressures should always be measured and set cold, so ambient temperature. My 65psi rear tyres (four on axle) all show nearer to 75psi at running temperature after 30 mins on a Motorway. I prefer 70psi hot, but 60psi is a little too low cold… life’s about compromise!

 

[Whippet93]

I was surprised, having fitted TPMS, the difference between one side, in the sun and the other in the shade on my van, up to 6PSI.

 

[poppycamper]

Tyre pressures should always be measured and set cold, so ambient temperature. My 65psi rear tyres (four on axle) all show nearer to 75psi at running temperature after 30 mins on a Motorway. I prefer 70psi hot, but 60psi is a little too low cold… life’s about compromise!

Exactly my point.. yes summer temps and winter temps are differant.. thus the reason I stated that in winter I was willing to ignore TPMS alarms and wait until temperatures and therefore pressures came back up...

 

[TrudeandDall]

Exactly my point.. yes summer temps and winter temps are differant.. thus the reason I stated that in winter I was willing to ignore TPMS alarms and wait until temperatures and therefore pressures came back up...

Better still. Reset your lower pressure in winter by blowing them up to the correct pressure. Then when things warm up again in spring reduce the pressure by letting the excess air out. TPMS alarms are there for a reason.....

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[poppycamper]

Better still. Reset your lower pressure in winter by blowing them up to the correct pressure. Then when things warm up again in spring reduce the pressure by letting the excess air out. TPMS alarms are there for a reason.....

Yes agreed.. but there is winter and there is winter!!! I was refering to the very occasional times when temperatures drops very low for a day or two.. like now when last 2 nights temp hit minus 9.5C.

 

[The Wino]

Better still. Reset your lower pressure in winter by blowing them up to the correct pressure. Then when things warm up again in spring reduce the pressure by letting the excess air out. TPMS alarms are there for a reason.....

I suppose it depends on the pressure once warmed up when driving. Our friends just got back from Portugal 20 degrees in the daytime 3 at night it would seem a bit over the top to change tyre pressure depending on the time of day! If tyre manufacturers produce tables of pressure against temperature are they saying set it at the same pressure no matter what the temperature or set it at the indicated pressure for the current temperature so as conditions vary it will be within a suitable range I suspect the second!

 

[Rapido925M]

Bear in mind that Gas Laws utilise Absolute (Thermodynamic, Kelvin) temperatures, so 3C to 20C sounds like a lot BUT 276k to 293k doesn't seem so much . In fact, it's a change of about 6% so 60psi should become 64psi IF that is the actual temperature change (probably due to ambient conditions). Once running, the tyre temperature will doubtlessly go higher.