[mudmav]

Hey guys I have just fitted 225/75/16 bfg km2 muddies to my GV the tyre placard says to run 26psi?

This seems low, my truck is fitted with bull bar winch and dual batteries

Does anyone have any idea what pressures I should be running in the road

[Scrawny]

26 psi

[Gwagensteve]

Certainly see no need to exceed 26. If you apply the 4psi rule you might find the ideal pressure is lower. I bet the km2's have a fair bit higher load rating than the stockers.

[mudmav]

Well I've just been for a drive I started at 32 psi based on the calculation in this link

http://users.tpg.com.au/klgreen/WK2_GC/ ... 0Guide.pdf

Tyres went from 31 psi to 34 psi on a 30 min drive, I'll play around a bit during the week but it seems 30-33 psi should be in about the right place

[henno]

I run 26 and less. 30-33 psi seems very high.

[Gwagensteve]

Suzuki don't know anything.

[atari4x4]

^^^ [FACT]

[mudmav]

Henno and gwagensteve have you checked how much your pressures change after high speed driving

[klutched]

I use the 4psi rule with mine, at 32 front 30 rear the pressures are within 4psi after a long drive. That's with 235/85R16s.

[henno]

Did you factor in changes in ambient temperature and adjust your tyre pressure according to the "4 psi rule"? No point checking your 'cold' tyres while it's 18 degrees when you set out only to stop later on when it is 32 degrees to test the 4psi rule.

[suz_rolly]

When I had my vit I ran 30 front and 28 rear that was at cold in 30x9.5r15
Offroad I ran 8-14 depending where I was

[mudmav]

Well it was a pretty steady 21 yesterday at my place all arvo so I assume there wasn't a lot of change in ambient temp

[atari4x4]

henno wrote:

Did you factor in changes in ambient temperature and adjust your tyre pressure according to the "4 psi rule"? No point checking your 'cold' tyres while it's 18 degrees when you set out only to stop later on when it is 32 degrees to test the 4psi rule.

THIS.

the 4psi rule is all well & good, when you drive for top level race team & you've got a pit crew to take note of every variable under the sun on every surface... i lived with a guy for many years who worked on & pit crewed on various race teams in the UK ranging from clio & porsche cup cars, 24hr endurance production cars & LM2 le mans race cars & everything inbetween. tyre monitoring is a vital part of reading the track & getting the most out of a car, but we're driving mass produced poorly handling 4wds, it's a matter of finding a solid benchmark & working off that, no 2 cars are the same... ideally you'd have a summer & winter starting pressure & same for dirt, sand, rock & mud.

[offtopic] my old house mate build a FQ400 evo lancer for a customer, was stripped & turned into a 24hr endurance car, built motor putting out a heap more, cage, all the suspension, massive fuel tan, fire bomb etc etc, was a spastic car when it arrived & was ballistic when built.... they tried every trick in the book to try & get the tyres to last a full tank, weeks of testing at silverstone & a few other tracks and managed to stretch it out to 3/4 of a tank, it was just never going to work as an endurance car as they had to keep feeding it tyres. the customer didn't want to turn the wick down, so they put rego plates back on it & it was a street car again, they bought a GT3 Cup car to go racing & were mid field straight off the trailer. [/offtotpic]