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Tandem axle tire pressures


KWT660HDT

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Howdy

 

I'm Wondering what other tandem axle trucks are running for tire pressures

 

I've got a 4200 lb pin weight and I've done nearly 10,000 miles with 95 psi all around without seeing any unusual tire wear. Seems like ok pressure all around but definitely pretty jumpy bobtail on gravel roads

 

Now I'm trying 100 psi in the front with 90 on the rears (fronts were too wobbly on gravel roads bobtail)

 

Has anyone run their tandem axles at 80 psi with trailers hooked up?

 

Doesn't look like the fronts at much less than 100 is a good idea

 

80 in the back would be better for Moab dirt roads but not sure it's enough for highway pulling the trailer

 

My truck weighs weighs 18,500lbs empty

 

Tires are 11R22.5

 

Thanks

2013 KW T660

485HP, 18 speed & locking tandems

2015 XLR 45' Toy-hauler

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This was discussed at length over the winter, I believe. The general concensus (sp?) was that the charts don't go low enough to reflect what our tires should have in them under very light loads. I'm running 80 psi with about 14k lb. on the drive axles. Considering that for the same tires and a 34k loading the recommended pressure is 95 psi, I'm safe, but have a rougher ride.

KW T-680, POPEMOBILE
Newmar X-Aire, VATICAN
Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row
Young enough to play in the dirt as a retired farmer.
contact me at rickeieio1@comcast.net

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Been running 100 steer 90 tandems at 26 k with 8 k on steer with 18 k on drivers with the Morgan 20 ft cargo van so the 11 ft tail swing makes the shaker ride like a stretch limo.....with the 12 ft flat bed it takes about 10 to 15 k to get the ride decent....have never found tandem tire pressure to make much difference in ride quality.....our air bags are too big for our light loads....that is where the long cargo van helps load the suspension...we are 64 ft 4 inches total length with the van on......

 

Drive on.......(90 f cool Death Valley nap time)

97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S

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Weigh and use specific tire charts with some safety margin included. Everyone is different (number of rear axles/singled axle position/configuration and amount of stuff/loads/tire size, etc). So, what others run may be interesting but not relevant to properly determining one's inflation pressure for their rig. We each need to know the facts/data for our own vehicle. the loads or inflation pressures may be the same as another but the only way to determine proper inflation pressure is to measure the loads and properly consult the inflation table for that tire. And the best (most accurate) measuring method for RV use is wheel position weighing. For trailer tires it is also important to know the kind of tire and any distinctions that may be associated with that type of tire as it is applied in RV use.

Susan & Trey Selman | email | HDT: '01 770 VED12 | 5er: '02 40' Travel Supreme RLTSOA | '16 Piaggio MP3 500 | '15 Smart Cabrio | Personal Blog | HHRV Resource Guide | HHRV Campgrounds | Recreation Vehicle Safety & Education Foundation |

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I guess my truck is different - maybe the 244" wheelbase - not sure

 

But I noticed a huge difference bobtail just going from 100psi all around to 90.

 

I'm going to try 100 psi steer and 80 on the drives until i can get properly weighed and see how it goes - I'm a lot less worried about it now seeing others running as low as 70 on the drives so thanks for the feedback

2013 KW T660

485HP, 18 speed & locking tandems

2015 XLR 45' Toy-hauler

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Weigh and use specific tire charts with some safety margin included. Everyone is different (number of rear axles/singled axle position/configuration and amount of stuff/loads/tire size, etc). So, what others run may be interesting but not relevant to properly determining one's inflation pressure for their rig. We each need to know the facts/data for our own vehicle. the loads or inflation pressures may be the same as another but the only way to determine proper inflation pressure is to measure the loads and properly consult the inflation table for that tire. And the best (most accurate) measuring method for RV use is wheel position weighing. For trailer tires it is also important to know the kind of tire and any distinctions that may be associated with that type of tire as it is applied in RV use.

Indeed Rv tires tend to be loaded to the sidewall limit or overloaded once wheel weight positions are determined.......most of the HDT trucks have nice tire load reserves in our RV uses......the Dollytrolley remains tandem and we unload every pound we can from the trailer and load it on the truck so that we remain below our goal of having no trailer tire is to not be loaded above 80% max load.......our truck tires seldom see much above 60% rated load.....

 

One subject seldom mentioned here on the forum is tire temps and lower pressures may tend to increase tire temps at the higher road speeds......we likely drive at somewhat lower speeds on our outback two lane roads but I will still tend to carry a bit higher tire pressure if the results are lower tire temps.......

 

We used to have a couple of 42 wheel lowboys and sometimes we would obtain tire company approval to carry 180% pressure increase with heavy steel wheels and derated speeds but then we were further limited to controlled temps as well sometimes we had to slow as low as 5 mph to keeps temps within limits......the tire engineers would say a cool tire is a happy tire.

 

Drive on..........( keep your cool.......tires)

97 Freightshaker Century Cummins M11-370 / 1350 /10 spd / 3:08 /tandem/ 20ft Garage/ 30 ft Curtis Dune toybox with a removable horse-haul-module to transport Dolly-The-Painthorse to horse camps and trail heads all over the Western U S

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