Tyre Pressure.

[notorious benny]

G'day guys, just been reading my manual for my new FG and recommended pressures are 30psi for the rears and 32psi for the fronts. 18 inch standard dunlops.

When I filled up today I decided to check the pressures guessing that they would have been correct from the factory. All four tyres were inflated to 40psi and the spare was at 47psi. I reset them to where recommended in the manual and then went to a second servo to check that the 1st guage wasnt out.

So what pressure should I be running for best life out of the tyres? Normal driving week to week consists of round town with the odd highway trip every second weekend or so. I also tow a go kart trailer which would weigh 600kgs approximately, is the old thought process putting 40psi in the tyres when towing still valid with performance tyres?

Please excuse my simple questions, this is my first car fitted with anything bigger than 16 inch tyres.

Cheers

Benny.

[FG-XR6T]

Hey mate,

Recently did a Advanced driving course In my FG XR6T. They recommended between 38 to 40psi all the time . Will wear the best and also protect rims from sh*thouse roads with lots of pot holls. Traction doesnt seem to be to much of a problem in dry. When tyres are cold will get wheel spin in 2nd at full power but once warm, grips bloody well. No point saying what the wet is like because you woiuld need massive tyres to stop them spinning when you have so much torque on tap.

Hope that helps.

Ben

[Benny]

Depending on how you drive and what your tyre wear is like will govern what is the best pressure I think. If you're just happy cruising around without too much hard cornering then 38-40 front and 38 rear. If you drive your car hard and enjoying throwing it into corners then I'd suggest around 42 front and 38 rear. This will help resist tyre roll and assist in keeping grip on the edges of your front tyres. This is what I ran with my old 18's and this worked out well. I'm currently running these same pressures in my FG with 19's and it seems ok so far.

[PHANTMXR6]

My tyre pressures weren't checked until after about 2000kms.

It was one of the things I overlooked due to being so overwhelmed with everything else that is the FG XR6T.

After I collected my composure though, I did check and they were all 34psi.

Not too bad I thought, and then I checked the sticker on the glovebox.

The recommended pressures seemed a bit low for my liking.

I recently did a 1600km round trip for a service and dyno reading and upped the pressure to 36psi for the trip.

Having rotated my tyres after the trip and now having 6400kms on board, I can say that running 36psi seems good for me.

There is no signs of any wear anywhere on the tyres in any position, which I'm pleased about.

Just a question for some that may not know, but your are checking your tyre pressures first thing in the morning when they are cold right?

I've found up to a 5psi variation from checking them cold and then running them for say 10-20kms and checking them again.

Cold inflation pressures are the best to check and adjust as air does strange things when heated.

[Benny]

I've found the easiest way to fill your tyres to the right pressure is to over fill them on your way home and then let them down to the correct pressure the next morning when the tyres are cool. Obviously the tyre pressures will go up when heated.

[PHANTMXR6]

Obviously the tyre pressures will go up when heated.

Not always obvious to some people.

I can't remember where I read it, but some dude couldn't work out why his exhaust tip was so hot!

Edited 08/09/08 11:31 AM by PHANTMXR6

[South]

Its the 4psi rule. Inflate them cold, drive until tyres have had a chance to warm up to a constant temp and check again, if they increase by 4psi then you are set... If they go up only a pound or two then you've pumped them too hard, if they go over by a few pounds then they are too low.

I find 38psi in all my tyres on all of my cars is spot on.

[notorious benny]

Found the actual tyre pressure placard on the vehicle itself. Its in the glove box of all places.........

Says 'maximum load' inflate tyres to 36 for the fronts and 39 for the rears. I feel more comfortable with these pressures than the 32 and 30 that it recommends for normal driving.

[spic]

I'm running 42 on the front and 40 on the back. Just found that 40 was a tad soft on the front with hard cornering.

[rockafellqeinstien]

Those presures are reasuring. I have been running 40 front and 38 rear in fg xr6t ute and thought maybe I shouldn't but it feels alot better on the straights and curves, I thought I might have wear problems, but on previous cars those presures were fine. The presures totaly changes the car feel. Meow if feels all nimbly bimby and much more enjoyable (if a tiny bit more bumpy). and it will help save those rims .