highway tyre pressures ?

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

Previously BFGs, currently Bridgestone Dueller LTs, next probably BFGs again. Travelling up north for our annual holiday we are absolutely at the limit of load, my mate running BFGs on his Prado has settled on similar pressures using the same approach.

If you really want to understand the effect of tyre pressures spend a day on a track playing around with different pressures and watch how it effects the vehicle handling.Low pressure kills handling and tyres.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

I'm interested also in what advice you took when deciding in increase front tyre pressures by 6-8psi when heavy & towing.

Did you run it over the weighbridge, refer to mfg's recommendations/type placard on prado/trial and (hopefully not) error?
Or all of the above?

It seems to be common that some are increasing front tyre pressures when also reducing front axle weights.
A reduction in front tyres pressures is necessary when reducing weight on the front end.

Yes - this is coming from a safety perspective and not tyre wear.

[krypto Avid PP Poster! Find all posts View Profile Close krypto]

I arrived at those pressures by monitoring heat build up and pressure change when driving, and by observing suspension sag and tyre deformation when stationary. From both it is pretty clear that there is a lot more load on the back when towing, although I haven't checked on a weigh bridge. I run pretty similar pressures front and back when not towing, unless the back is full loaded when then I might run slightly more pressure at the back. This approach comes from a mix of experience and my background as a mechanical engineer..