Dually tow vehicle tire pressure

[Hamnet]

Ok. Dually Truck door jamp sticker says rear pressure 65 pounds and front 70. My 5th wheel is 12995 dry and 15000 loaded. I run 80 pounds in rear tires when towing which is maximum rating. I run 70 in the front.
My question is the 70 pounds in front good or is it under inflated. Thanks in advance foe replies.

[Sabretooth007]

My opinion for what its worth is your both right.

Impulse is talking old school and Cummins 12v98 is talking New School.

[Me_Again]

Impulse24 wrote:

As to Education !! Yer right I guess I'll burn my CDL and teaching certificate with the Driving Instructor Certification.

So with all of that you do not know what an inflation table is for or why manufacturers have them? Chris

[Cummins12V98]

"If your that sure post a link !!!
Its a pity that RV's aren't required to go over the scales and have inspections the same as Trucks, there again if they did there would be a lot less RV's on the road. In the mean time Suit yourself, I strongly suggest you have a meat wagon follow you, "

You asked for a link, sorry I don't know how to do that so this will have to do. Meat Wagon???

Looks like the chart you requested shows 35psi as the lowest psi. Why would they have this chart if it's not ok to use it??? As Chris noted I have WAY more capacity at 35psi than I need running BobTail. My rear axle weight is 4K empty.

[Cummins12V98]

Google the tire size Chris mentioned and "inflation chart". They make those for a reason.

I did show how perfect my tires wore with long mileage earlier running my psi's I run.

[Impulse24]

So the newer GM duallies have LT235/80R17E tires, which at 65 psi are rated to 2680 each. The front GAWR appears to be 5600 pounds. So at 65 pounds inflation the tires are unrated for the max axle rating. So are you sure it says 65 pounds all the way around.

BTW at 35 pounds dual the tire is rated at 1570 each or a total of 6280, which is fine for casual everyday used include runs to box stores giving well over a ton of capacity in the bed.
Chris

Chris, I just noticed your post and you deserve a response,
So here it is from the horses mouth as they say..

Tire Size: LT235/80R17
Tire uses LT-Metric tire size standard, with tread width of 235 mm or 9.25", aspect ratio of 80%, sidewall height of 188 mm or 7.4", and rim diameter of 17" or 431.8 mm.
Tire Load Index: 120
Tire has a load index of 120, with maximum load carrying capacity of 3086 pounds or 1400 kilograms per each tire.
Tire Speed Rating: R
Tire has a speed rating of R that allows for maximum service speed of 106 miles or 170 kilometers per hour.
Maximum Tire Pressure: 80 psi / 5.52 bar
Tire has a maximum tire inflation pressure of 80 psi or 5.52 bar per tire as set by tire manufacturer.

Always use the correct tire inflation pressure recommended by the vehicle manufacturer, or as stamped on the tire sidewall.

Hope this helps..

[Impulse24]

Respectively you need to educate your self!

Look at the weight/inflation chart for 17" stock DUALLY rear tires. 35psi is MORE than needed to PROPERLY inflate the 4 rear tires



If your that sure post a link !!!
Its a pity that RV's aren't required to go over the scales and have inspections the same as Trucks, there again if they did there would be a lot less RV's on the road. In the mean time Suit yourself, I strongly suggest you have a meat wagon follow you,
Low tire pressure causes heat which causes blow outs in the same way over inflation does.
when you see your tires wearing on the side, don't check the Alignment because it will be your tire pressures being too low causing excessive wear. Tires that are too low on pressure cause the center of the tire to rise leaving contact with the road which means the edge/side of the tire is the only contact you have with the road. Which creates a longer braking distance and control problems.
You obviously have never been told until now brakes don't stop the vehicle they only slow the wheel rotation, The friction between the road surface and the tire tread is what stop the vehicle. And although it means nothing to quite a lot of people having correctly inflated tires gives better mpg.
As to Education !! Yer right I guess I'll burn my CDL and teaching certificate with the Driving Instructor Certification.

Edit : - I'm done with this topic....

[Me_Again]

Impulse24 wrote:
35 PSI! I don't even drop that low when I'm off Roading.

The vehicle manufacturers and the tire companies spend hours working out tire pressures. Having a pressure lower than that recommended pressure could lead to shortened tire life and is a potential safety hazard. The air in the tire supports the vehicle, so less air causes the tire to increase in heat and work harder than it is supposed too.

The sidewall markings on the tire for inflation are tire industry standards based on size and usage. In other words they are regulations from the Government for Maximum inflation and load, they are not vehicle specific.

Plus if you read the sticker on the door with the tire pressures you will note it states, something like this vehicle conforms to all Applicable Federal Motor Vehicle Standards at the time of Manufacture.
Hence this is a Government Sticker (DoT) and should be adhered to.

Also a Tire Guy at Discount may look as a know nothing, but they train and get certified to do the Job.

I will keep running 65 psi all round loaded or empty, as recommended by Discount Tire and the DoT Stick not forgetting the tire manufacturers side wall pressure!!

So the newer GM duallies have LT235/80R17E tires, which at 65 psi are rated to 2680 each. The front GAWR appears to be 5600 pounds. So at 65 pounds inflation the tires are unrated for the max axle rating. So are you sure it says 65 pounds all the way around.

BTW at 35 pounds dual the tire is rated at 1570 each or a total of 6280, which is fine for casual everyday used include runs to box stores giving well over a ton of capacity in the bed. Chris

[Cummins12V98]

Respectively you need to educate your self!

Look at the weight/inflation chart for 17" stock DUALLY rear tires. 35psi is MORE than needed to PROPERLY inflate the 4 rear tires.

[Impulse24]

35 PSI! I don't even drop that low when I'm off Roading.

The vehicle manufacturers and the tire companies spend hours working out tire pressures. Having a pressure lower than that recommended pressure could lead to shortened tire life and is a potential safety hazard. The air in the tire supports the vehicle, so less air causes the tire to increase in heat and work harder than it is supposed too.

The sidewall markings on the tire for inflation are tire industry standards based on size and usage. In other words they are regulations from the Government for Maximum inflation and load, they are not vehicle specific.

Plus if you read the sticker on the door with the tire pressures you will note it states, something like this vehicle conforms to all Applicable Federal Motor Vehicle Standards at the time of Manufacture.
Hence this is a Government Sticker (DoT) and should be adhered to.

Also a Tire Guy at Discount may look as a know nothing, but they train and get certified to do the Job.

I will keep running 65 psi all round loaded or empty, as recommended by Discount Tire and the DoT Stick not forgetting the tire manufacturers side wall pressure!!

[Cummins12V98]

Me Again wrote:
The mentality of those that do not know better or fail to call a tire manufacturer for advice is to default to max sidewall. If you talk to a tire company like Michelin they will tell you that over inflation for weight carried leads to a higher chance of impact damage and reduced braking as a result of the decreased contact patch.

Chris

TRUE! They will also tell you that ride quality will suffer.

[Me_Again]

The mentality of those that do not know better or fail to call a tire manufacturer for advice is to default to max sidewall. If you talk to a tire company like Michelin they will tell you that over inflation for weight carried leads to a higher chance of impact damage and reduced braking as a result of the decreased contact patch.

Chris

[Cummins12V98]

Impulse24 wrote:
What some people don't understand is there are two different standards at play with tire pressures.

1. The Sticker in the door is a DOT standard of maximum pressure for the ORIGINAL TIREs that came with the vehicle, which in turn were used in accordance with the design and manufacture of the vehicle and its specifications.

2. The max pressure on the tire is the max the amount of air the tire was designed to safely be used at. That pressure is also calculated to allow for expansion when the tire gets hot.

Therefore in realty if you are using original tires then the DoT sticker should be your Maximum Pressure.
And if you are buying after Market the maximum on the tire should be used. Regardless of weight in no way should those pressures be exceeded.

My Dually states 65 all round on the sticker, and that is the pressure Discount Tires also recommends,
My 5th wheel tires are also 65 psi max and I run on 65 psi all round and have no problems.

Sorry but that is not true. The door sticker is what air pressure is required to support the axle weight that the truck is rated for. My FAWR is 6,000# and 80psi front tires is what is need to properly support that load. My RAWR is 9,750# and 65psi is required to support that weight. Your part about " The Sticker in the door is a DOT standard of maximum pressure for the ORIGINAL TIREs" is not correct.

Discount tire recommends what the door sticker says. That is what they fill to. They would NOT fill my rears to 35psi as that is all that is needed to safely run solo with my dually truck. It's called CYA!!!

[Impulse24]

What some people don't understand is there are two different standards at play with tire pressures.

1. The Sticker in the door is a DOT standard of maximum pressure for the ORIGINAL TIREs that came with the vehicle, which in turn were used in accordance with the design and manufacture of the vehicle and its specifications.

2. The max pressure on the tire is the max the amount of air the tire was designed to safely be used at. That pressure is also calculated to allow for expansion when the tire gets hot.

Therefore in realty if you are using original tires then the DoT sticker should be your Maximum Pressure.
And if you are buying after Market the maximum on the tire should be used. Regardless of weight in no way should those pressures be exceeded.

My Dually states 65 all round on the sticker, and that is the pressure Discount Tires also recommends,
My 5th wheel tires are also 65 psi max and I run on 65 psi all round and have no problems.

[Cummins12V98]

Me Again wrote:
It is just amazing as to the number of people that over inflate their dual rear wheels to 80 lbs. Just about all call for 65 pounds inflation at max load on the rear axle. So many seem to know more than the truck and tire manufacturers. Chris

EXACTLY!

Many don't even come close to needing even 65psi as their RAW does not require that much pressure. I used to run 60psi towing my 18-19K DRV with 4,500# pin weight and after 40K on these tires they look darn good and over 1/2 were towing miles. I ran 35 solo on these.