Tyre pressures - How cold is cold ?? - the_bandit
Winter is drawing closer and the ambient overnight temps are beginning to take a tumble from the norm.

I maintain my tyre pressures at the recommended 35psi all round (when cold).

However overnight temps a couple days ago fell to 5 Deg C with an accompanying wind that made it feel like zero! When I started the car and checked the pressures I was down to 33psi all round.

So question is how cold is cold? What temp do manufacturers rate the PSI at? Should I be topping the pressures up when down to these colder temps?

Your thoughts welcome.

{dropped car make/model as this question applies to all makes/models}

Edited by Dynamic Dave on 30/09/2008 at 11:28

Tyre pressures - How cold is cold ?? - L'escargot
If the tyres were set at 35psi at a normal ambient temperature (approx 20 degC) then they should be OK at all ambient temperatures. Even when it's really cold the tyres will soon warm up when the car is driven.
Tyre pressures - How cold is cold ?? - Old Navy
normal ambient temperature (approx 20 degC)>>


Where do you live Mr Snail?

Edited by Old Navy on 30/09/2008 at 10:12

Tyre pressures - How cold is cold ?? - Cliff Pope
If tyres warm up in use anyway, regardless of the ambient temperature, then what is the point of checking the pressures when cold? Wouldn't it be better and more convenient to specify the normal running pressure?
Tyre pressures - How cold is cold ?? - L'escargot
If tyres warm up in use anyway regardless of the ambient temperature then what is
the point of checking the pressures when cold?


The cold temperature is nearer constant than the running temperature.
Tyre pressures - How cold is cold ?? - L'escargot
>> normal ambient temperature (approx 20 degC)>>
Where do you live Mr Snail?


OK, 20 degC yearly average inside my shell, 10 degC yearly average outside. tinyurl.com/3zwjwh
Tyre pressures - How cold is cold ?? - craig-pd130

When it says "cold tyre pressures", read = "tyre pressure taken before you start driving"
Tyre pressures - How cold is cold ?? - Mapmaker
When it says "cold tyre pressures" read = "tyre pressure taken before you start driving" and the car has not been parked in the sun or a greenhouse.

Tyre pressures - How cold is cold ?? - kithmo
and the car has not been parked in the sun or a greenhouse.

I've noticed that with the car parked against the hedge on a cold morning with the sun on the other side, there was a difference on one side to the other.
Also noticed that parking on a slope (sideways) I have had slightly higher readings on the lower side of the car ???
Maybe digital tyre gauges are too accurate ;0)
Tyre pressures - How cold is cold ?? - Rustyw
This has always intrigued me. How do I get the car to the petrol station to check the tyres without driving it? Realistically, how long does it take for the tyres to warm up and if I do check the tyres when I fill up with fuel how much allowance should I make for warm tyres?
Tyre pressures - How cold is cold ?? - Stuartli
If you only have a comparatively short distance to drive to the garage, it doesn't make any difference.

I once asked a Michelin tyre specialist about tyre pressures and how accurate they needed to be and his response was that, providing the balance between the front and the rear tyre pressures was maintained (i.e. if one or the other was higher or lower), a slight deviation from the correct pressures was acceptable.

In fact I keep my tyre pressures about 3psi higher than the stated figure to cover driving on motorways or at higher than usual speeds; it also aids fuel consumption to a degree.

Edited by Stuartli on 01/10/2008 at 00:58