What tire pressures are you running on your van?

[Bikersmurf]

For what it's worth, I'm running 233/75r16 load range E tires on my 1997 Dually Crestline 'New Era' Ambulance. Tire pressures are 65 Front and 55 Rear as the Door sticker states... Planning to Run a chalk test in the near future.

The previous Duallys wore even (but quickly) at 51 (max)... Turns out the PO put passenger tires on an 9000 lb rig... All I can say to that is... "Thanks... For a steal of a deal on a great rig".

 

[bknudtsen]

Thanks for the feedback guys.

To the best of my recollection, VANdiana weighed right in at 8000lbs empty prior to the winch. At 7500 lbs (prior to the final 4x4 conversion) I ran 36-38 psi out to Minnesota and back with no wear issues, pulling, wallowing, etc. Those 35x12.50-17 Toyo MT's are a 65 psi max tire, so if you are pushing 10,000lbs loaded, I would consider bumping it up into the upper 40's for highway travel to avoid overheating the sidewalls. One thing you can't really do is compare the bigger flotation sizes to the smaller 265/75-16 E-rated 80 psi wagon wheels.

 

[mk216v]

To the best of my recollection, VANdiana weighed right in at 8000lbs empty prior to the winch. At 7500 lbs (prior to the final 4x4 conversion) I ran 36-38 psi out to Minnesota and back with no wear issues, pulling, wallowing, etc. Those 35x12.50-17 Toyo MT's are a 65 psi max tire, so if you are pushing 10,000lbs loaded, I would consider bumping it up into the upper 40's for highway travel to avoid overheating the sidewalls. One thing you can't really do is compare the bigger flotation sizes to the smaller 265/75-16 E-rated 80 psi wagon wheels.

Probably about right weight-wise.
I'm going to try 42-44psi COLD for street and see how that does.
I'm always impressed with how this big guy drives and handles, especially with floaters! :smiley_drive:

 

[bknudtsen]

The Toyo MT's are super stout. My 305/70-17 Nitto Terra Grapplers are rated at 3640 @ 65psi but they seem to have more sidewall bulge than the Toyo's at similar pressure. For comparison, I am running them at 55psi COLD on my 8100lb-ish truck. They are a little bit chattery at that pressure, but at 50psi they seemed to bulge a bit too much. Maybe I will split the difference.

Funny thing is that VANdiana felt lighter than Agnes at basically the same weight. Except when braking...

 

[Nomad1]

I just got Kuhmo AT51 D rated for my 99 Astro and I just did the chalk test and they are now set at 40psi cold....
I do run tires at 20psi off road smother ride on rough logging roads and washboards...

 

[Bikersmurf]

The chalk test has served me well over the years... Wear has been very consistent with the pattern the chalk wears off. I've always erred on the side of a couple extra pounds rather than softer.

And I agree, you can't compare pressures across different sizes... Just like 55 with duallys will carry a lot more than a single at 55. Sidewalks play a minimal role... Consider how much weight a flat tire supports. It's about the pressure over the size of area.

 

[calebmogul]

E350 PSD UJOR 4" 285x75x16 BFG's. 8000lb rig. 65-68 lbs. 45,000miles so far, plenty of tread still left. Been running them at 60 lbs for the past week, and it's definitely a nicer ride. Been airing down to 26-30 lbs. for offroad.

 

[mk216v]

The Toyo MT's are super stout. My 305/70-17 Nitto Terra Grapplers are rated at 3640 @ 65psi but they seem to have more sidewall bulge than the Toyo's at similar pressure. For comparison, I am running them at 55psi COLD on my 8100lb-ish truck. They are a little bit chattery at that pressure, but at 50psi they seemed to bulge a bit too much. Maybe I will split the difference.

Funny thing is that VANdiana felt lighter than Agnes at basically the same weight. Except when braking...

Yeah, why UJOR's RSC 14.5" front brake upgrade is the next big mod for the big guy. Stock 13" rotors aren't very safe with more GVWR. Out of curiosity what size front rotors does your Cheavy have?

 

[bknudtsen]

13" as well.

 

[mk216v]

13" as well.

<banghead>
I have no idea what these truck engineers were thinking. 13" front rotors for a big heavy truck? Compact passenger cars now have 13"(or larger if they're performance models) front rotors!!
Makes baby seals cry.

Keep the tire pressure info coming guys, great stuff here.

 

[Randall Dee]

2006 E250 RB/5.4. Just last weekend I stopped at a weigh station. I was right at 6700 lbs. I'm running 285/75/16 E rated Cooper S/T Maxx at 42psi at all 4 corners.

 

[FarmerFrederico]

Great thread! As MK said before - I'm driving a UJOR 4x4 6" E350 V10 RB unweighed van but probably around 8,500lbs right now. BFG KO2 35x12.5x17 tires with a max of 65psi which could theoretically maxed out could carry a 12,750lb vehicle.

For everyday paved road driving I'm going up and down steep canyons with sharp curves that are often not banked well even for sometimes 15, 20, and 30 mph speed limits. It's easy to come into corners too fast around here...so while lower pressure might give me a good feeling out on the flats and in town and also pass a chalk test, it is too squirmy for the canyons. I've driven the canyons at 40, 55, and 60psi. Couldn't notice a difference between 55psi and 60psi, but 40psi felt like I really had to drive conservatively. I'm going to drop from 60psi down to 50psi and see how that feels and do another chalk test. Hopefully that will be a good middle ground because gravel roads are sometimes part of the everyday mix to get to trailheads so it would be nice to get to the lowest possible pressure to take the edge off all of my close to home driving scenarios. If I'm hitting the interstate for a few days, I'll bump it back up to 60psi for more efficiency.

For off road I've been as low as 35psi but I'm going to drop to 25psi next time and check the bulge.

 

[bknudtsen]

<banghead>
I have no idea what these truck engineers were thinking. 13" front rotors for a big heavy truck? Compact passenger cars now have 13"(or larger if they're performance models) front rotors!!
Makes baby seals cry.

Yes, but my truck has hydroboost.

Oh... And now 52 psi all around.

 

[mk216v]

I'm looking forward to doing this chalk test.

Yes, but my truck has hydroboost.

Oh... And now 52 psi all around.

Lucky! MG has duplicates of the custom parts he built for his setup--which I told him I want him to install in VANdiana along with the RSC brakes.