Tyre pressure when warm - runflat indicator reset

S

SteveD

Member
How much does the pressure get affected when the tyres are warm and how long does it take for them to cool down?

I just had my wheels refurbed and when driving home on dual carriageway the runflat indicator came on. Thought probably just not reset when wheels put back on - and I had forgotten in the glow of my shiny new wheels, but the car did feel a bit skittish when joining dual carriageway. Thought better be sensible and drove home from there at about 50.

Stopped for about 15mins at homebase store then drove half a mile to garage and checked pressures. The tyres are standard Bridgestone runflats and did not feel warm at this point. They were set as 2.5 bar - door says 2.3 rear and 2.1 front so I changed the pressure. They felt OK on the 1.5mile drive back to home.

Before I reset the indicator, I thought I would seek advice on whether I should now reset indicator or wait until they are fully cold and drive back to the garage to re-check them.
 
Ah OK. I always thought the pressure was higher when hot?

My manual says set it and then drive for a few minutes.
 
yes the pressure is higher when hot, but the tyre pressure monitor uses wheel speed to tell if the wheel is low on pressure...compared to the other wheel speeds, the wheel with the low pressure turns faster than the others !

Yes drive until the light goes out after pressing the button :)
 
In general tyre pressures should be set when cold, you need to add about 4 to 5psi (0.3 bar) if they are hot when checked, but I'm not sure how long they take to cool?
 
Thanks. Just to be safe I set them again next day.
They were all .15-.2 bar lower than they should be.

Sent from my Nexus 7 using Tapatalk 4 Beta
 
You must log in or register to reply here.
Back
Top Bottom