Outer Limits 4x4 Board

G'day All,
Had a look in the FAQ area, and also searched the site, but couldn't find any answers.

I'm running BFG A/T's (30 X 9.5's) on my Rocky, and trying to find what the recommended tyre pressure in them is. Went to put air into them the other day, and the guage said they were at 32 PSI, , yet they were still bulging a bit at the bottom. Put a bit more air into them and it got rid of most of the bulge, but I'm thinking the pressure in them now just seems overly excessive (38 PSI).

Any tips??

Cheers

Floody

What size rim are the 9.5 wide tyres on ??

yes you should get a little bit of bulge to make the tread sit flat on the ground and to wear evenly.

I had the same issue when I put wider tyres on my Magna 205 - 215....they look 'flat' on the bottom, but there is still 32 psi in them.

were these measured hot/cold?
there is some rule about making 4 pound allowance to cold/hot tyres.

i ran 32-35 on 31s

Floody_1985 wrote:G'day All,
I'm running BFG A/T's (30 X 9.5's) on my Rocky, and trying to find what the recommended tyre pressure in them is.

Have you had a look in the glovebox to see what's recommended- there should be a sticker? I normally add ~4PSI to whatever is recommended, that seems to work well for most vehicles I've owned.

I run 32 on the front and 30 on the rear. This is because of steal bullbar and winch.
Ive also got 30" BFG A/T's.
Your car is a bit heavier then the Feroza i imagine so you will need to take that into account.

Basically keep adusting the pressure until your happy with ride, dont worry about a buldge either.

Had a look at the sticker, and they say like 26 or something ridiculous like that, . If I were to run that, my tyres would near be flat!

Think they're 15 inch rims that they're on (the stock rims that came with the 93 model Rocky's).

Measured them when they were hot. Had a look at them this afternoon again, and they had a slight bulge in the bottom, and looked about right. I'd say the pressure would be about 34 or so when they're cold, as they were.

See how I go, might play with the pressures a touch here and there.

Cheers

Floody

All tyres will bulge at the bottom. If you pump them up high enough to get rid of the bulge then they will most likely be over inflated.

The recommended pressure for Feroza's is only 23PSI!!! I run around 30PSI and increase the rear if loaded up.

I played around with mine until there is a good balance between the handling and the ride roughness.

Lower pressures will cause more of a 'boat like' ride with cornering and stuff...lol (also increase outer tread wear)
And too high of a pressure will cause you too feel every bump in the road.. (also increase central tread wear)

I run mine on 36 psi at the moment, which is a good balance I feel.. I had them on 32 and it was a bit floatey round corners and stuff.. and tried them on 40psi and felt all the bumps.. so lowered it a touch.
I've always thought the tyre placards on every car I've owned are rubbish.. too low of a pressure for me.
Just play around and see what you like best

I run 30x9.5R15 BFG A/T's on 7 inch rims as road tyres. I run them at 28 psi normally, but go up to about 32 for long trips, and 35 if I am towing the camper/loaded.