Car Tire PSI question

[davesXX01]

Simple Dave, 32 cold is correct. Sustained highway driving, run 35.

Do you fully understand what I mean by cold though? If not, check your tires first thing in the morning, before you drive it! If it's at 32 then fine, if it's at 30 and you drive to the gas station and by then it's 35 then add air until its at 37 as the tire has already heated up.

BTW, Nice car!

[Para045]

I have had two F100's a 78 4wd before and a 79 2wd now and usually run Goodyear Wranglers or similar and I usually run them at around 48psi - my workshop manual say's between 36 and 50 psi cold for 10R15 Lt's and the tyre say's 50psi at max load but after driving these vehicles for probably 20 years I have found that higher pressure is better. Yes low pressure gives a softer ride and possibly slightly better wet weather grip, but handling and tyre life is reduced considerably :icon_nono: I do drive my vehicles fairly hard and fast and on some of the bumpy roads near where I work the higher pressures do make for a bumpy ride but I can live with that for the extra ~20% extra milage ( kilometerage does not sound right ) that I get from the life of the tyres I have also found the same with my wifes lowered 5.0l V8 ex police Falcon - when we first got it, it came with Dunlop Lemans 205mmx65x15" and they were great handling/gripping tyres at 42psi ( 44psi max on tyre 36psi recommended for that size on the door jamb ) but wore more and handled fairly ordinary at 36psi ( although rode softer and more comfortably ). Since then she has had Hancooks (evil handling,no grip, fast wearing marshmellows that felt dangerous at any sort of cornering speed ) and currently Khumho's which are somewhere in between ( good grip, reasonable milage but more sidewall flex/body roll ) but still better at higher pressures ( although the missus finds the ride nicer at 38psi they handle worse and wear more at speed ):icon_think:

JMHO

[beondwacko]

Being that I've been "into" car tires for some 20+ years now ( my father is a bit of a tire freak ) , I don't ever recall seing a non V or higher rated tire with a max pressure rating higher than 35psi. Dave, I'd use the tires ratings as a saftey guideline. If they have a max rating of 44psi (the ride will suffer and so will the wet traction at this number ) but the response will pick up a bit and so might your mileage slightly, but life is a compromise and so are inflation pressures. It will take a little experimenting to find a happy meduim, but I would not suggest running at max pressures.