I run 31 if filling from cold and 33 from hot.

is that 31 on front and rear when cold or just the front?

I'm with FOCA on this and run at 39-40psi front and back. The tyres give max pressure ratings on their side walls - my Michelins state max 51psi so I am nowhere near that limit. I notice a positive effect on handling and mpg at these pressures compared with recommended values and noticed straight away when they were reduced by the garage after a service. It doesn't affect wear as I still get more than 50k miles per set.

For my standard wheels I run pressures as per the door sticker - 33psi front and 30psi rear, then 34 all round for the 19's.

Expect it'll be the extra weight of a diesel lump or 2.5T which dictates running higher pressures front than rear.

I know that there are many arguments for and against high/low pressure tyre levels in regards to fuel economy and speed but unfortunately the solid fact is that running tyres over a car manufacturers recommended pressure will result in loss of grip and an increased level of uneven wear and a higher risk of losing traction/stability resulting in the likelyhood of swapping ends and entering the pearly gates backwards with a surprised look on your face.

What the tyres are rated to is not the important factor, the recommended pressure for a car at different loading levels is.

http://www.drivers.com/article/354/

http://www.michelin.co.uk/tyres/learn-share/care-guide/ten-tyre-care-tips

Having driven a new car in monsoon conditions on the M6 and thinking it felt rather skittish, then finding the tyres were still at transit pressures I can vouch that 44psi all round in a Mk6 Fiesta isn't a good set of pressures to try running!

I know that there are many arguments for and against high/low pressure tyre levels in regards to fuel economy and speed but unfortunately the solid fact is that running tyres over a car manufacturers recommended pressure will result in loss of grip and an increased level of uneven wear and a higher risk of losing traction/stability resulting in the likelyhood of swapping ends and entering the pearly gates backwards with a surprised look on your face.

What the tyres are rated to is not the important factor, the recommended pressure for a car at different loading levels is.

http://www.drivers.com/article/354/

http://www.michelin.co.uk/tyres/learn-share/care-guide/ten-tyre-care-tips

two good articles there clive.

they make sense and deserve a read through.

I think the best answer to any one looking advice on tyre psi is stick with the label on the door or the handbook as these are manufacture recommendations.

I think if you do this you cant go far wrong lol! I will be running mine from now on on the fully laden recommendations on the door label as Its me the wife and 2 kids and usually a boot full most of the time so for me personally I think this might be the best bet in terms of psi recommendations.

when our patrol cars were mostly Focus estates we were instructed to keep pressures at 31psi (cold) and the arches were marked to enforce this.

I have atrended collisions and crashes where tyre pressures were a contributing factor (but not necessarily a primary cause).

Pure fact is that excess pressure equals less tread surface on contact with the road and therefore less grip.

Unless you enjoy going south on a northbound cariageway I say stick to what the car companies say.