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I guess it is possible but I would think pretty unlikely.
How to Improve Dirt Road Ride? (1 Viewer)
- Thread starter Ben Whipple
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Depending on rig weight, tire, etc, 30 psi maybe higher than ideal for highway speeds.
If you're unloaded in the rear you can go lower there. It's all relative to the load. One of my 7.50 r16 tires is rated to carry close to the whole weight of my truck at max psi. I have close to the same weight front to rear (kids in a MWB) and if spending equal time on and off road I run about 23 psi.
If on the highway I air up to above the factory recommended pressure of 27.5 to about 30psi to factor in the weight of the winch. This gives a very noticable on increase in acceleration. If I have more of a load in the rear I add pressure accordingly. My truck is a half ton and the factory recommended tire pressure for the rear is about 42psi (for a full load.)
On washboard or river rocks I stick with about 18 because my wheels do not have any provisions other than the air pressure to keep the bead from sliding towards the center of the wheel. 18 makes it way more comfy.
Pete
If on the highway I air up to above the factory recommended pressure of 27.5 to about 30psi to factor in the weight of the winch. This gives a very noticable on increase in acceleration. If I have more of a load in the rear I add pressure accordingly. My truck is a half ton and the factory recommended tire pressure for the rear is about 42psi (for a full load.)
On washboard or river rocks I stick with about 18 because my wheels do not have any provisions other than the air pressure to keep the bead from sliding towards the center of the wheel. 18 makes it way more comfy.
Pete
No dramas mate, over here, more dirt than pavement usually means hours of dirt just to reach pavement!
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/this x2\
My '68 rode like a pogo stick the first time I put a set of 33's on it. They were aired up for the K5 Blazer I'd borrowed them off of. More than 1k in vehicle weight difference.
Fast forward 30 years. My '68 now weighs 1000lbs more with upgrades, spare parts and accesories. It's the only vehicle in the fleet on 33s, and thy're at 22 for the street/dirt roads...with even tire wear.
AND X100 on the shock/spring mods also suggested.
Hth
Mark
I run splits and tubes.
35 psi for everything (highway, dirt roads, gravel roads, and off-road) except when I risk getting stuck (deep mud, sand, beach-stones, deep snow) at which time I air-down to around 15 psi. (I like to keep my decisions simple.)
I don't air-down for rocks because I'm not into competition rock-crawling and when I encounter them (such as crawling over river boulders), my tyre-grip is always good enough at 35 psi and I want to lessen the risk of sidewall damage. (Airing-down wouldn't present any problem as far as "breaking a bead" because of my tubes, but I prefer to protect my sidewalls and my diesel idles over river boulders with ease at 650rpm in 1st gear low-ratio!)
If corrugations get so bad they start jack-hammering the undercarriage, then I just slow down further (still at 35psi), regardless of how slow I end up having to go. (Hopefully I'm in such a lonely place that there's no chance of anyone banking up behind me but if there is, I just pull over and let them pass.)
My policy is NEVER to be in a hurry. And I forever remind myself that my interest in 4-wheel-drives stems from my love of the outdoors. So scenery (such as the desert-scrub in Australia) that is boring for some is of never-ending interest to me (and I regularly scan it for interesting difficult-to-spot wildlife as I drive).
(New Zealand doesn't really have sufficient land mass or the type of terrain to experience real corrugation issues or real isolation/solitude in a 4WD vehicle.)
And when driving in Australia I used to get rewarded by regularly seeing those who'd overtaken me in a cloud of dust stopping to their change shredded tyres. (And just looking at the number of spares they were carrying on their roof-rack and their overall loading often made me giggle, although I do understand the pressure they put themselves under trying to fit their "outback adventure of a lifetime" into their brief annual leave allowance.)
35 psi for everything (highway, dirt roads, gravel roads, and off-road) except when I risk getting stuck (deep mud, sand, beach-stones, deep snow) at which time I air-down to around 15 psi. (I like to keep my decisions simple.)
I don't air-down for rocks because I'm not into competition rock-crawling and when I encounter them (such as crawling over river boulders), my tyre-grip is always good enough at 35 psi and I want to lessen the risk of sidewall damage. (Airing-down wouldn't present any problem as far as "breaking a bead" because of my tubes, but I prefer to protect my sidewalls and my diesel idles over river boulders with ease at 650rpm in 1st gear low-ratio!)
If corrugations get so bad they start jack-hammering the undercarriage, then I just slow down further (still at 35psi), regardless of how slow I end up having to go. (Hopefully I'm in such a lonely place that there's no chance of anyone banking up behind me but if there is, I just pull over and let them pass.)
My policy is NEVER to be in a hurry. And I forever remind myself that my interest in 4-wheel-drives stems from my love of the outdoors. So scenery (such as the desert-scrub in Australia) that is boring for some is of never-ending interest to me (and I regularly scan it for interesting difficult-to-spot wildlife as I drive).
(New Zealand doesn't really have sufficient land mass or the type of terrain to experience real corrugation issues or real isolation/solitude in a 4WD vehicle.)
And when driving in Australia I used to get rewarded by regularly seeing those who'd overtaken me in a cloud of dust stopping to their change shredded tyres. (And just looking at the number of spares they were carrying on their roof-rack and their overall loading often made me giggle, although I do understand the pressure they put themselves under trying to fit their "outback adventure of a lifetime" into their brief annual leave allowance.)
Last edited:
Downey
SILVER Star
Front springs always did have one more leaf than the rear springs, that's because of heavy engine on front, empty bed in back. Test equipment was mounted on some popular off road race vehicles and they found that you are pulling 9 times the forces on the front as the rear. When you hit an off road bump with a stiff suspended rear end and an empty bed, the rear end bounces up into the air. When the rear end bounces up into the air it compresses the front springs. Then the compressed "spring loaded" front springs unload and bounce the rear end into the ground. Then the front to rear rocking begins. Remedy, ultra soft rear springs and rear shock valving. Ivan Stewart use to say "I sincerely hope my rear bumper drags every inch of the Baja 1,000, THAT'S WHY !!!!!
no, you'd have a nicer ride with lower pressure on dirt, particularly if there are washboards
30psi should be fine.
LOL. For what? I recently did a 12 mile section of Henness Pass Rd and most of it pretty much sucked with 20 psi.
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Look at his avatar!
Downey
SILVER Star
Soften up the rear end bro !!!!!
He asked if 30 psi is OK for the street. You don't think 30psi will work?
I don't know what Henness Pass Rd is. Is that a off-road trail or something? I don't recall hearing of it.
"Do you guys think 30 is OK for pavement and dirt road?"
Google it. It's a historical road through the sierras from Reno to Marysville that got passed over when others were paved. It's awesome. It doesn't get much maintenance, though, so there are long sections of baby-head rocks. 12 miles took over an hour.
Looking east towards Jackson Meadows Reservoir:
Looking roughly north at the Sierra Buttes:
I've always used the chalk test. With mods, my front and rear weight is the same.
When I ran 31x10.50 Michelin XCAT, I ran 22 PSI for 40k miles with even wear... wore like they were overinflated and still had 10k or more left.
33x12.50 Yokohama Geolander A/T, 20 PSI wore like they were overinflated... had life left at 35k miles.
Now running 33x10.50 BFG A/T at 25 PSI, probably a little harder than necessary, but with current gas prices, trying to do every thing I can to help economy and make the steering easier.
Off road, 12 PSI on gravel roads... 15x8 rims. Never lost a bead other than when I ran 10 PSI, bounced, bunged a rim and lost almost all pressure before the bead gave out.
When I ran 31x10.50 Michelin XCAT, I ran 22 PSI for 40k miles with even wear... wore like they were overinflated and still had 10k or more left.
33x12.50 Yokohama Geolander A/T, 20 PSI wore like they were overinflated... had life left at 35k miles.
Now running 33x10.50 BFG A/T at 25 PSI, probably a little harder than necessary, but with current gas prices, trying to do every thing I can to help economy and make the steering easier.
Off road, 12 PSI on gravel roads... 15x8 rims. Never lost a bead other than when I ran 10 PSI, bounced, bunged a rim and lost almost all pressure before the bead gave out.
