Midwestdrifter
Engineer In Residence
Re: Exploring Australia From The Left
I do regularly deflate when driving on rough roads. I vary my pressure with the speed at which I want to drive, as lower pressures means lower speeds.
For speeds of 65kph, I need around 30 rear and 25 front minimum based on my last time on a scale.
I will go down to 20 rear and 15 front on very soft surfaces. However I need to keep my sustained speed 35kph or under, and unseating a bead is possible with aggressive driving.
I base my deflation pressures on the sidewall height rule.
My tires are 245/75 profile. The sidewall measured from the rim to the ground is about 175mm at normal pressure (60 rear 55 front). I reduce the sidewall height by ~15% for crap roads, and 25% for sand etc.
For those unaware, at 25% sidewall height reduction the tire reaches its optimal footprint. This is as long as it will get without the sidewalls rubbing on the ground. This means optimal flotation and maximum bump absorbing.
Anyways, the van wasn't rattling itself to pieces. Other than my aftermarket radio coming out, it was pretty uneventful (other than the slow onset of insanity).
For those interested, the van weighs about 8600lbs. 3800lb on the front axle, and 4800lbs on the rear axle.
MWD.
Glad you are enjoying some of OZ. Can I remind you that you will damage your vehicle if you continue to drive on such high tyre pressures. That corrugated road
is about 12-15 psi country. Eric.
I do regularly deflate when driving on rough roads. I vary my pressure with the speed at which I want to drive, as lower pressures means lower speeds.
For speeds of 65kph, I need around 30 rear and 25 front minimum based on my last time on a scale.
I will go down to 20 rear and 15 front on very soft surfaces. However I need to keep my sustained speed 35kph or under, and unseating a bead is possible with aggressive driving.
I base my deflation pressures on the sidewall height rule.
My tires are 245/75 profile. The sidewall measured from the rim to the ground is about 175mm at normal pressure (60 rear 55 front). I reduce the sidewall height by ~15% for crap roads, and 25% for sand etc.
For those unaware, at 25% sidewall height reduction the tire reaches its optimal footprint. This is as long as it will get without the sidewalls rubbing on the ground. This means optimal flotation and maximum bump absorbing.
Anyways, the van wasn't rattling itself to pieces. Other than my aftermarket radio coming out, it was pretty uneventful (other than the slow onset of insanity).
For those interested, the van weighs about 8600lbs. 3800lb on the front axle, and 4800lbs on the rear axle.