Tire capacity question

[Rving life]

What would be load rating of a tire at 65psi, if the load rating is 2235 at 80 psi. The million dollar question is at 65 psi will the tires safely tow a fifth wheel with a hitch weight of 1910 pounds. Ram dually with specs on rear tires inflated to 65 psi.

[NH_Bulldog]

Personally, I would only set tire pressure at the level specified on the tire and loading information sticker whether on the truck or trailer. If I am not loaded and/or towing for a longer period of time, I will drop my tire pressure on the truck (like they are now since it’s winter). My trailer tire pressure is ALWAYS set according to the sticker, period.

If you are trying to soften the harsh ride of a 1 ton dually, it probably isn’t going to happen.

[flybouy]

Originally Posted by Rving life

What would be load rating of a tire at 65psi, if the load rating is 2235 at 80 psi. The million dollar question is at 65 psi will the tires safely tow a fifth wheel with a hitch weight of 1910 pounds. Ram dually with specs on rear tires inflated to 65 psi.

For what purpose? If your rims are only rated for 65 psi max then but D tires and inflate to the placard pressure. If your rims can handle 80 psi and you wish to upgrade from a D to E tire then fully inflate to 80 psi.

[chuckster57]

I have always used the max pressure on the sidewall of my truck tires when hooked up to the fiver.

[rhagfo]

Originally Posted by Rving life

What would be load rating of a tire at 65psi, if the load rating is 2235 at 80 psi. The million dollar question is at 65 psi will the tires safely tow a fifth wheel with a hitch weight of 1910 pounds. Ram dually with specs on rear tires inflated to 65 psi.

Where do you get 2,235# rating?

Our 2016 Ram dually has 235/80-16 E rated tires Load at 80 psi is 3,085# single and 2,835 dual.

So at 80 psi the four tires would support 11,340#, the payload sticker stated to inflate rear tires to 65 psi to support the axle rating of 9,750# so each tire only needs to support 2,437.5#.

You might check that you have the correct tire size and load range on your Ram DRW.

We have a pin of 2,700#, and run the rear tires at about 55 psi when towing.

[fjr vfr]

Originally Posted by Rving life

What would be load rating of a tire at 65psi, if the load rating is 2235 at 80 psi. The million dollar question is at 65 psi will the tires safely tow a fifth wheel with a hitch weight of 1910 pounds. Ram dually with specs on rear tires inflated to 65 psi.

You don't state the tire size here. It's easy knowing the size, you just plug in the numbers to Michelin's or other brand's "pressure and load" chart. You can also find the same info on sites like Tire Warehouse web site. It's all there.

One other note, trailer tires are a completely different animal. They are LOAD rated tires and are meant always to run at maximum rated pressure, unlike vehicle tires which have more flexible side walls and are able to to run at different pressures according to the vehicle specs.
Also running pressures to low creates excessive heat and can lead to early failure. If you are towing I'd always error on the side of the higher pressure...it's safer than running to low.

[CWtheMan]

Originally Posted by rhagfo

Where do you get 2,235# rating?

Our 2016 Ram dually has 235/80-16 E rated tires Load at 80 psi is 3,085# single and 2,835 dual.

So at 80 psi the four tires would support 11,340#, the payload sticker stated to inflate rear tires to 65 psi to support the axle rating of 9,750# so each tire only needs to support 2,437.5#.

You might check that you have the correct tire size and load range on your Ram DRW.

We have a pin of 2,700# and run the rear tires at about 55 psi when towing.

The proper nomenclature for your tires is LT235/85R16. The LRE have a maximum load capacity of 3042# at 80 PSI. All ST/LT designated tires weight ratings are by the load range lettering system.

The correct inflation pressures for your OE tires are found on the vehicle certification label, vehicle tire and load placard and in the vehicle owner's manual. (Tow vehicles may have vehicle manufacturer supplemental tire inflation placards).

The USTMA standards manual will tell you to NEVER use less inflation pressures than recommended by the vehicle manufacturer.

[rhagfo]

Originally Posted by CWtheMan

The proper nomenclature for your tires is LT235/85R16. The LRE have a maximum load capacity of 3042# at 80 PSI. All ST/LT designated tires weight ratings are by the load range lettering system.

Get your facts straight, the numbers are directly off the tire sidewall. These are LT truck tires mounted on a Ram 3500 DRW.
The OP also stated these were on the Ram DRW.

[CWtheMan]

Originally Posted by rhagfo

Get your facts straight, the numbers are directly off the tire sidewall. These are LT truck tires mounted on a Ram 3500 DRW.
The OP also stated these were on the Ram DRW.

My facts are correct. Load index numbers on LT tire sidewalls are for the purpose of adding the tire's speed letter.

It would be a double standard to go by the load index numbers when a load range letter is molded into the tire sidewall.

If your tire is a 235/85R16 - I've never seen that size designation - it's a European designation for a passenger tire. They all use the load index numbering system for load capacity.

[jasin1]

Before joining the forum i never imagined that tire specifications and choices were one of the topics that could cause a fight to breakout in a bar

[sourdough]

Originally Posted by jasin1

Before joining the forum i never imagined that tire specifications and choices were one of the topics that could cause a fight to breakout in a bar

Another Corona and lime please...

[CWtheMan]

My RAM dually had LT235/80R17 LRE tires. 80 PSI for those tires WAS 3085#.

[Dacheedah]

No benefit to running a tire under rated pressure.
At 80psi, a 265/75R16 10ply itire will carry 3,085 pounds of load.
At 60 psi on a 10ply tire, the tire's load carrying capacity is reduced to 2,314 pounds per tire. from https://www.yournexttire.com/trailer...flation-chart/

[notanlines]

Sometimes I feel like a Libertarian trying to join a political argument after too many Coronas.

[gearhead]

When driving unloaded for any amount of time I run my Ram rear tires down to 42PSI from the placard spec of 65PSI. The fronts stay at 80PSI to support the heavy diesel.
If I don't air down the rears it's a spine jarring ride. At 42PSI it's somewhat better.

[wiredgeorge]

This is starting to sound familiar... Since everyone owns tires, everyone seems to be an expert. Why do OEMs put a tire inflation placard on every vehicle.

OP... read the tire inflation placard on your vehicle and abide by what it says. Can't go wrong if you have the original size tires.

[Rving life]

2235# is off the tire for dually rating. Bridge Duravis 500 tires
235/80/17 tire on Ram.
I was able to locate load rating table on tire for different psi levels.

[chuckster57]

I haul my fiver with the max pressure for the highest load rating. Had a rear inner tire go BOOM in Missouri with the old fiver hooked on. Was able to ease off the road and change to the spare. if I was at a lower pressure/load rating it might not have turned out the same. JMHO YMMV

[JRTJH]

Originally Posted by Rving life

2235# is off the tire for dually rating. Bridge Duravis 500 tires
235/80/17 tire on Ram.
I was able to locate load rating table on tire for different psi levels.

Something to consider:

Way back when, Ford and Firestone were "implicated" in a recall for "rollover crashes with the Explorer SUV when using Firestone tires"

Seems that Ford "recommended" setting the tire pressure lower than Firestone's recommended low setting for those tires when used in an applicaton for that vehicle.... As I understand it, Ford's recommended pressure "was on the Firestone load/pressure chart by axle/wheel weight listings" but was "too low for the application, even though it was reflected "on the chart"...

You might consider that even though the tire load/pressure chart goes down low enough to list a weight that can be supported by a pressure (a number that fits in a box), it may not be safe to run at that pressure when towing a trailer, given the dynamics of the forces a trailer exerts on the stability of a tow vehicle.... Ford "discovered" that when Explorers started landing wheels up when operated at conditions that Ford hadn't tested "on the track"...

So, airing down for a softer ride may not maintain the stability in all driving situations.

Just something else to consider when "going solo outside the manual's recommendations".....

[jasin1]

I have a 6x12 cargo trailer that i recently started using again…new carlisle C rated tires ..it’s a single axle..i ordered carlisle D rated but they were back ordered from walmart so i went with the stock rated tires for now.
since the tires sit outboard of my truck i use, i can watch the tire deflection…trailer isn’t loaded heavy but interesting to see how much the tires bulge out when going over bumps..was looking at trans eagle 10 ply to replace as they were recommended by Big Truck Big RV youtube