My 4Runner came with BFG T/A off-road tires on it. 30x10.5 if it makes a difference. They’re non-stock so the manual for the car is no help on how much pressure to run in these for on-road use. The sidewall says the load rating is X pounds at 50 psi. (Sorry - don’t remember “X” - but shouldn’t matter).
Does this mean that running the tires at 50lbs for general on-road use is the expectation? This is my first truck, all my other cars just said “32 psi”. No qualifiers.
I just aired them up this morning - truck seems like a performance vehicle now. I was negligent, most were around 30 psi when I started, one was 25 psi. Bad boy!
When off roading, in general the pressures run are much lower than on highway use. For sand dunes you might use as little as 10PSI.
If you can find a copy of The Off-Roaders Handbook the authors cover this subject quite well.
If you do find a copy look through the pages, and you may see pictures of a automotive doper’s hands and forearms.
OK, since you asked nice. Grab a beer and let me tell you the story.
One of the authors of the book, Spence Murray, did publicity for the off road racing team that I worked for.
Spence has been a fixture in the off-road community since before there was one. Spence won the very first Baja 1000 in a Rambler (he knew where he was going, and didn’t get lost) This guy has spent more time in low range than most people have ever spent off pavement. he is also one of the nicest men I have ever met.
Anyway Spence is a promoter. A world class promoter. Spence promoted a new truck out of a truck manufacturer with the promise it would be featured in some magazine articles about off roading. He got an advance from a publisher for the off road handbook. He then set out to write it. He would get an idea for a chapter that needed to be written. He would then approach a magazine editor with a proposal for a story. They would buy it. He would then call guys that made whatever part he needed for the story and ask if they wanted their product featured in an article he was writing about subject X. The manufacturer of course wanted to be featured, so they would send him a free whatever.
Spence would then call us up and ask if we could spare sometime to fabricate something for the truck. We would of course be happy to have Spence mention us, so come on down.
Anyway I did several projects for magazine articles during the year that I worked there.
When the first article was published it had pictures of me mounting something. All of the pictures were of my hands and wrists. Nothing of the rest of me. So I said the least you could do was get my face in one.
When Spence did the next article, he made sure that my face showed in at least some of the pictures.
The editor cropped the pics so that only my hands showed. When that issue came out, Spence came by with a copy. He walked in and grabbed me by the forearm. He turned my arms over and looked at my palms exclaiming “I know those hands, those are famous hands!”
Me: “WTF?”
He then pulls the article out and apologizes for the editor cropping the picture. After that it got to be a joke, he would take pics with my showing all of me, and the editor would without fail crop the pics. I think there is one or two where you can see my uniform shirt with the “Rick” sewn on.
Anyway when Spence has sold enough articles, he gathered them all together sent them all off to the book publisher, and a book was born.
So Spence got all the stuff for the book free. He then sold each chapter twice. Now do you see why he is a world class promoter?
When you get the book, look for the chapter on an on-board air compressor. I designed that, and did all the fabrication for that chapter, those are my hands! I did a bunch more, but that is the one I recall without digging out my copy to look for my hands.
30 to 35 psi should be good for on road use. If you run with really heavy loads then going to 50 psi can make sense. I have 30x9.50 tires on my Ranger, usually aired up to 30 psi. When I use it to haul gravel or tile the tires look pretty bad at 30 psi with a full load in the bed, so I increase it to 50 psi until I’m done hauling.
If this is your first truck, be aware that these off road tires can wear in odd ways and that balancing and rotating the tires frequently will help you get the most out of them. My truck has Dunlop Mud Rovers (a very aggressive tread pattern) and while I love the traction they provide I have to rotate and balance about every 3,000 miles.
