Thanks Scott. Good information to know. I never thought about using the rim diameter as a reference for lowering the tire pressure. I've always just started at 1/2 the recommended street tire pressure.
Important to note, the lower you go, the more ground clearance you loose. Also, not al A/T are ok with running trails at 17psi. Rocky or washboard I don't drop mine below 21 (265/65/17)
Great questions. Shifting into 4WD (or driving an AWD) on unimproved surfaces reduces both wheelspin (even imperceptible) and wheel hop by having both pushing (rear axle) and pulling (front axle). Just a way to reduce impact and preserve trails for future travelers.
Even better, if a manufacturer publishes tyre pressure data for off-road use, follow those. Michelin publish them for the 4x4-O/R - known also as the XZL - for on-road use, tracks and sand up to 65 km/h (40 mph), and for emergency flotation up to 20 km/h (12 mph). It generally tracks along 65-70% of normal for tracks and sand, and 30-40% of normal for emergency soft. I have the complete table if you want it?
As a Tyre Tech for more than 4 Decades , Yes airing down will lengthen the Tread Length But It Will NOT Make the Tread Any Wider than it is Already, And Riding on the Sidewalls Is NOT Increasing the Tread Width, You Guys Always try to say that it makes them wider BUT It Dose NOT, The Tread Patten Can NOT GROW In WIDTH.
Thank you for the feedback and comment. In general terms (as it varies by section height and construction) 80% of the increased flotation area comes from the carcass length, and 20% from the width. It is important not to confuse the tread face with carcass width (which also includes sidewall tread on many tire models), as carcass width under low pressures does contribute (although marginally) to increased flotation. This is most evident in snow, sand, and mud. When crossing glaciers, we rely heavily on the increased flotation that comes from the sidewall as well.
Thanks Scott. Good information to know. I never thought about using the rim diameter as a reference for lowering the tire pressure. I've always just started at 1/2 the recommended street tire pressure.
Thanks for the feedback and for watching
Does cargo weight need to be factored in? Still safe to run 80psi tires at 40 psi on a 2500 Heavy Duty pickup with a FWC camper weighing 1800lbs?
🙏❤️ Love Scotland ❤️🙏
Important to note, the lower you go, the more ground clearance you loose. Also, not al A/T are ok with running trails at 17psi. Rocky or washboard I don't drop mine below 21 (265/65/17)
What ATs have you found are not rated for trail pressures?
Scott, dig the watch. what is it?
That one is my dad's vintage Seiko from 1969 (chronograph automatic)
Super awesome piece!!
You also recommend engaging 4WD early on unpaved roads. Why does 2WD tear up unsaved roads? How does 4WD prevent that?
Great questions. Shifting into 4WD (or driving an AWD) on unimproved surfaces reduces both wheelspin (even imperceptible) and wheel hop by having both pushing (rear axle) and pulling (front axle). Just a way to reduce impact and preserve trails for future travelers.
Even better, if a manufacturer publishes tyre pressure data for off-road use, follow those. Michelin publish them for the 4x4-O/R - known also as the XZL - for on-road use, tracks and sand up to 65 km/h (40 mph), and for emergency flotation up to 20 km/h (12 mph). It generally tracks along 65-70% of normal for tracks and sand, and 30-40% of normal for emergency soft. I have the complete table if you want it?
We do love the XZL for all the wrong reasons (grin), and they look fantastic on the Defender 110.
As a Tyre Tech for more than 4 Decades , Yes airing down will lengthen the Tread Length But It Will NOT Make the Tread Any Wider than it is Already, And Riding on the Sidewalls Is NOT Increasing the Tread Width, You Guys Always try to say that it makes them wider BUT It Dose NOT, The Tread Patten Can NOT GROW In WIDTH.
Thank you for the feedback and comment.
In general terms (as it varies by section height and construction) 80% of the increased flotation area comes from the carcass length, and 20% from the width.
It is important not to confuse the tread face with carcass width (which also includes sidewall tread on many tire models), as carcass width under low pressures does contribute (although marginally) to increased flotation. This is most evident in snow, sand, and mud. When crossing glaciers, we rely heavily on the increased flotation that comes from the sidewall as well.