Gravel Road Tire Pressure

Airing down isn’t just for more traction, it’s also for vehicle longevity. Sure, you can rip those washboards at 60mph and 60psi. But it’s easier on you, your truck, and everything else you’re carrying at 20psi.

I had the stock Wranglers down to ~14psi doing Mount Antero. I’ve had E rated Falken AT3W down to 6. 6psi, over a huge surface area is a lot of force. There’s about 600 in^2 of total surface area on a 32” tire with a 16” rim. If you take 1/4 of that (probably about the surface area that holds the tire on the rim at the contact patch), that’s still 900 pounds of force you need, as a direct side load, ignoring friction (which could also be a few hundred pounds, or more), to “potentially” break the bead.

 

Ah I didn’t catch what “superdirty” meant. Thanks for cluing me in.

 

Nope. Every 3/4 ton and up truck I've seen call for 60-80psi.
nevermind, just saw your other post haha 80psi in a taco would be a little rough to say the least

 

I’ve never been to Wyoming, but my buddy has been out there several times on dirt biking trips. I can’t say I’ve done 160 miles on dirt alone, but it’s certainly possible to do that in Minnesota. There are several 100 mile gravel road bicycle races in the state. Although i don’t live in the most densely populated state, after a quick google I discovered it’s a lot more dense than I thought compared to Wyoming. 70 people/mi^2 compared to 2 people/mi^2. Lol. Minnesota is closer to California (253 people/mi^2) than Wyoming.

A vast majority of gravel roads in Minnesota are well maintained because they are they are the a primary transportation system in farm country. We do have quite a lot of “minimum maintenance” and forest service roads as well, but I’ve never thought it was necessary to air down my tires for a road.

 

Well that's what's funny is that I never thought I'd want to air down on a gravel road either until I moved to Idaho! I'm not even in Wyoming anymore. All I know is that one 140 mile trip here made me go buy a compressor and some extra valve cores

 

Great information I really appreciate it!

AND I COULDNT AGREE MORE WITH "Sure, you can rip those washboards at 60mph and 60psi. But it’s easier on you, your truck, and everything else you’re carrying at 20psi."
Some people in here acting tough like they just drift around the blind 180 hairpins all day long and not
1. Get busted by a ranger
2. Die.

 

The problems I see with 20 psi at hiway speeds is that the tire was likely not designed for that. The rolling resistance will increase which will cause it to heat up excessively and reduce efficiency (mpg and acceleration) as well as decreasing lateral stability, and increase the chance of catastrophic failure.

That said, I’m guilty of driving many miles on a leaky tire that I forgot to fill up and I’ve never had one blow up and send me into the ditch.

 

32 psi on gravel roads. I'll throw it in 4hi, and good to go.

 

4hi for a gravel road? Put it in 2hi and send it.

 

4hi reduces wear and tear on your drive line, reduces the development of washboards, and is safer. If you get stuck in 2wd, switching to 4wd will very rarely get you out. You bought a 4wd for a reason, why be afraid to use it.

 

Huh? We are talking about gravel roads. A Corolla could master one. What are you talking about? Regardless my post was meant to be light hearted humor.

 

I guess “roads” is relative. Plenty of forest service “roads” in Colorado will go from 20+mph to sticky spring mud faster than you can stop. But they’re numbered, public roads that show up on the Nav unit in the Tacoma.

 

Here too, but they aren’t usually made of gravel.

 

Not a single thing you just said makes any sense.

 

In regards to FSR/gravel tire pressures, I go to 26 psi “hot” on e-rated K02. That puts me at about 22 PSI before the tires warm up.

I like this pressure because you can do a quick jaunt on the pavement if you need to without the truck handling like a bowl of jellow.

Airing down on FSRs is not about traction, it is all about not rattling your truck and everything you own to death. If you live in an area with smooth clay FSRs with no potholes, I would stay at normal PSI and send it. In the rainy potholed northwest, it is worth the effort.

As far as going into 4Hi when you hit the gravel, take my advice: I was travelling a recently made, brand new logging road
, freshly topped with gravel. This road was glass smooth on a dry summer day. No need at all for 4x4. However I was in 4hi because I had just exited a more spicey trail onto this road. I’m cruising along this road, when out of nowhere a 50 foot section of the shoulder collapses beside me as I’m driving. The new road had been undermined by recent rains and they clearly had not got the culverting figured out yet. The road surface on one side was just a crust above a long hollow cavity. The passenger side of my truck dropped down as the road collapsed, with the truck landing on it’s A-arms, sliders, and rear axle at speed. Because I was in 4hi, I could react quickly and pin the throttle in an attempt to save the truck from rolling sideways into the 8-foot deep ditch beside the road. My front tires, which were at the leading edge of the collapse, clawed like mad, sending up a huge rooster tail of gravel, as I fought to get the truck back up on the road. A super close call, and one of my scariest “oh shit” moments ever. In 2WD, my rear driver side tire, which had all the traction, would have stoved me into the ditch, which was deep enough that the truck would have rolled on its side.

Always be in 4Hi on gravel roads. Whatever extra fuel you might burn, is money well spent.

 

Actually, that makes all the sense in the world to me. I had the same experience on my 2wd bike. In 1wd, I could hear the drive line whirring as it loaded and unloaded over washboard. In 2wd, it was smooth and happy. I've not heard but felt the same in the Taco. Instead of losing speed in 2Hi, 4Hi keeps the drive line settled and at a constant speed.

 

What 2WD bike do you have?

 

This thread had taught me that the term gravel road is very specific to your location in the world.

 

???

 

Absolute truth. It’s not the same everywhere. Also, how heavy one’s Tacoma is will have a dramatic affect on what is the right tire pressure.