Tire Pressure help?

[AH64ID]

See this is why got confused. I appreciate all the responses.

I am currently 50 front and 65 rear and the ride is a little harsh. My tires are oversized so that helps. I will try dropping them down into the 40's to see how it feels. For long highway trips I will return to my current pressures to help with heat. For washboard roads I'll drop to 35 and try that.
Thanks everyone!

Drop to charted pressure for the weight, it’s enough even for long highway trips.

For washboard roads you can go even lower since you aren’t traveling at speed. The chart pressures are for the weight at the tires speed rating, so when you’re driving below the tire speed rating you don’t need as much air. Be sure to air up before hitting higher speeds

The tire pressure charts are a joke. Run those pressures on the highway for a couple hours and see where your temps are at, it won’t be good. A larger size tire should support the same weight at a lower pressure, I wasn’t able to keep the temperatures in check without running full pressure.

You’re approaching GVWR. Why not run the tires at the specified pressure and address the suspension as the issue

I think something else was going on, I’ve run tire pressure chart pressures for nearly 20 years on all kinds of rigs (jeeps to 3500’s) and never had any tire run anything close to as hot as you’re mentioning, temps are always in check without running max pressure unless I’m at max load for the tire.

 

[EBS-P]

I'm in a wheelchair full-time for 34 years and I feel every bump in my spine. I'm looking for the best comfort ride I can. That's what's important to me. I know there are trade-off's but I'm ok with that.

Everyone has their own sense of what comfort is. That's great.

Road surface imperfections can be mitigated by tire pressure. Big bumps needs addressed with suspension modifications. Your front axel could be hitting bump stops on big bumps. More damping could help but then it might not be as good absorbing the small bumps.

 

[Green Maned Lion]

I'm in a wheelchair full-time for 34 years and I feel every bump in my spine. I'm looking for the best comfort ride I can. That's what's important to me. I know there are trade-off's but I'm ok with that.

Everyone has their own sense of what comfort is. That's great.

Not trying to define anything, my friend. Just pointing out the different factors.

If you are in a position where comfort is the most valuable thing to you, assuming you don't go too crazy and risk a blow out, inflate them as little as is safe. It will absolutely improve your ride. I spend a lot of money on silly things because my wife has a weird sensitivity to roundup and hyper-reactive hypoglycæmia. I also recently lowered my tire pressure because my wife's bad back became more important than a mpg or two of fuel economy.

I think, though, the dumbest thing somebody can do is try and find out the one correct answer to any given problem. The answer for one person with such and such a weight and distribution who wants to hyper mile is different to the one whose back is more sensitive. It is best to know the various factors and how they affect each other, and then decide what compromises you are willing to make to best suit one's own needs.

 

[Green Maned Lion]

Road surface imperfections can be mitigated by tire pressure. Big bumps needs addressed with suspension modifications. Your front axel could be hitting bump stops on big bumps. More damping could help but then it might not be as good absorbing the small bumps.

Bottoming out? I have never experienced anything like that even driving in the moonscape roads of Willingboro.

 

[Maslin]

I think something else was going on, I’ve run tire pressure chart pressures for nearly 20 years on all kinds of rigs (jeeps to 3500’s) and never had any tire run anything close to as hot as you’re mentioning, temps are always in check without running max pressure unless I’m at max load for the tire.

Based on the Toyo chart, my 3500/4600lb ish van should run 35 psi in the front (well over at 3820 pounds) and 48 in the back. I believe I started at 46/55ish (because 35/48 is insane).

Bumped the rears to 70 and the heat problems went away immediately. Nothing else changed, just the pressure.

 

[tom2turbo]

I'm in a wheelchair full-time for 34 years and I feel every bump in my spine. I'm looking for the best comfort ride I can. That's what's important to me. I know there are trade-off's but I'm ok with that.

Wider Tires provide more flotation allowing lower pressures resulting in greater shock absorbing effects. Install wider tires.

 

[AH64ID]

Based on the Toyo chart, my 3500/4600lb ish van should run 35 psi in the front (well over at 3820 pounds) and 48 in the back. I believe I started at 46/55ish (because 35/48 is insane).

Bumped the rears to 70 and the heat problems went away immediately. Nothing else changed, just the pressure.

Very odd indeed.

Well over what?

I have no issues following the charts, even when it "seems" low. My last CTD was nearly 9K lbs empty at 5400/3500 full of fuel and just me in it. I ran 50/35 empty without any heat issues on the stock sized tires. I run even lower in rear in winter for better traction.

Last summer in the van I ran 48/40, which was still too much but didn't want the TPMS getting angry, without any heat issues.

I need to check but I think my DD Jeep is at 18 psi right now, but on 285/70R17s.

 

[run4x4]

Based on the Toyo chart, my 3500/4600lb ish van should run 35 psi in the front (well over at 3820 pounds) and 48 in the back. I believe I started at 46/55ish (because 35/48 is insane).

Bumped the rears to 70 and the heat problems went away immediately. Nothing else changed, just the pressure.

Should I set the pressure -5 PSI of door sticker recommendation to account for expansion after driving for a while.

 

[AH64ID]

Should I set the pressure -5 PSI of door sticker recommendation to account for expansion after driving for a while.

No, all pressures are cold pressures. Don’t adjust pressure based on hot pressure.

 

[QwkTrip]

Should I set the pressure -5 PSI of door sticker recommendation to account for expansion after driving for a while.

Door sticker is specifically at the GAWR. It's just one of the numbers in the tire inflation chart for the stock tire size.

 

[run4x4]

Door sticker is specifically at the GAWR. It's just one of the numbers in the tire inflation chart for the stock tire size.

My van is 6900 lbs when not in trip mode, when we head out on trips I think it's 7400-7600 lbs with passengers. I don't want to keep adjusting the air pressure based on weight. It's been set to 70R/50F which gets to 73/56 after driving a few dozen miles. Since I swapped out the rear shocks to Blistein B6 camper I love the way it drives, superb control on the highway and relaxed driving. I was thinking about reducing the front pressure to 40 psi, but I might reduce it to 46 as per the door sticker recommendation.

 

[EBS-P]

Should I set the pressure -5 PSI of door sticker recommendation to account for expansion after driving for a while.

All pressures we talking about and the door card list are cold pressures. Don’t ever correct for the tire warming up. That can be a slippery slope if an uninformed person stops after an hour and checks and sees pressures are up and lets air out they may/will end up with an under inflated tire.

 

[QwkTrip]

Just learn what pressure promotes even tire wear and run it there. The inflation tables get close to that number, and then you fine tune through observation. Or run a couple PSI higher for better cornering. There is no one exact answer, just do something that works.

If you want a quick answer in just a couple drives , then measure tire temperature across the width of the tread immediately after you pull off the highway. But you have to be able to interpret the data to understand whether it's a pressure issue or an alignment issue.

 

[AH64ID]

My van is 6900 lbs when not in trip mode, when we head out on trips I think it's 7400-7600 lbs with passengers. I don't want to keep adjusting the air pressure based on weight. It's been set to 70R/50F which gets to 73/56 after driving a few dozen miles. Since I swapped out the rear shocks to Blistein B6 camper I love the way it drives, superb control on the highway and relaxed driving. I was thinking about reducing the front pressure to 40 psi, but I might reduce it to 46 as per the door sticker recommendation.

Interesting, I thought the 2000kg front axle was standard on 4x4/AWD but I guess not. Maybe that’s just on cargo not pass vans. Who knows.

Anyways, 46/70 is safe for max loads in your van. If you’re wanting to lower it then get individual axle weights when loaded on your next trip. Often you can just pull into a closed weigh station and use the scales, they are normally left on. Based on 7600lb GVW I’d guess you have some room to lower pressure, especially in the rear axle.

 

[dm07]

Very odd indeed.

Well over what?

I have no issues following the charts, even when it "seems" low. My last CTD was nearly 9K lbs empty at 5400/3500 full of fuel and just me in it. I ran 50/35 empty without any heat issues on the stock sized tires. I run even lower in rear in winter for better traction.

Last summer in the van I ran 48/40, which was still too much but didn't want the TPMS getting angry, without any heat issues.

I need to check but I think my DD Jeep is at 18 psi right now, but on 285/70R17s.

My 2022 has a temperature read out as well as pressure. When in travel mode I run the rears at 70 and reduce the fronts to match the tire temps...usually 43 front.

My Agilis Crossclimates seem very happy.

FWIW, 65 rear raised the temperatures noticeably.

 

[AH64ID]

My 2022 has a temperature read out as well as pressure. When in travel mode I run the rears at 70 and reduce the fronts to match the tire temps...usually 43 front.

My Agilis Crossclimates seem very happy.

FWIW, 65 rear raised the temperatures noticeably.

My van also has temp readings and tire chart pressure doesn’t run hot. My trailer TPMS also does temp and I run chart pressure on the 5th wheel without too much heat either. I do have LT’s on the 5th wheel.

 

[depark]

UPDATE: So I took the advise of others and I can say the difference was immediately noticeable! All I can say is it's like driving a completely different vehicle. I took a little bit of time to adjust my suspension settings as well. I lowered my pressures to 45 psi all the way around and the change is amazing. The van actually seems to track better. Corners beautifully on the highway still and no squishy feeling. Best of all it eats up all the highway bumps.

For reference my van is 8400 lbs. Running Nitto Ridge Graplers (LT 285/70R17). I have a then Van Compass Stryker 6.5 suspension On my van. This is the Adapt electronic adjustable shock system (discontinued). I have my highway settings set to 0.8 GeForce and 1 second duration. My off-road settings are 0.8 GeForce and 4 seconds duration. The settings are very good and comfortable.

As a side note after a 2 Hour Hwy. trip my tires only gained 2 psi in that time. I think that's a win
thanks again for your help everyone
Cheers
Darryl

 

[EBS-P]

FWIW, 65 rear raised the temperatures noticeably.

From? To? When it was how hot outside?