Tyre pressures Dunlop 275/35 ZR21 on A8L

[Turbo Tony]

Originally Posted by Conan_the_Librarian

When I did one of my advance driver course with an ex Met Police examiner we discussed tyre pressure in non standard tyre and wheel combinations.
His recommendation is to set up at a datum (say 34 in your case); then drive the car the manner you intend (urban, motorway, track) and once the tyres are at operating temperature measure them again. You are looking for an increase of 10%. If it's higher than 10% then the tyres were under inflated when cold. Under 10% then they were originally over inflated. It's all about sidewall flexing. Of course it also depends on the manner in which the car is being driven. There are no, one pressure suits all occasions.

Neat tip!