Tire inflation while towing heavy

[The Evil Twin]

Remember, the tire inflation chart is exactly what it says- MAXIMUM load for a given pressure. So at 60 psi, you are maxing that tire out. IMHO that’s not ideal. You have more sidewall flex and tread ply/ carcass tension. That builds heat as @LWS witnessed. There is a rule of thumb that the ratio is 4:20. For every 20*f increase in temperature tire pressure increases by 4 psi. Hot tires (and brakes) tend to fail.
When towing heavy, I always go within 5 psi of the tire max inflation in the rear and start at door jamb listed pressure in the front. I’ll adjust front of the steering feels light or tracks weird on the highway.

 

[LWS]

Thanks I had never heard the 20% rule. My issue is that 65 psi is maximum listed for the Mickey Thompsons I have the Tremor. So I was already at cold pressure maximum when I headed out.
Should I go ahead overfill to 70 (above the limit) or live with the increase in pressure as I drive ( I should note this increase was seen on an 18 hour drive over the Canadian Rocky Mountains).

 

[HeavyAssault]

Should I go ahead overfill to 70 (above the limit) or live with the increase in pressure as I drive ( I should note this increase was seen on an 18 hour drive over the Canadian Rocky Mountains).

The limit is the limit. NO reason to go over the recommended Cold PSI numbers for the tire/load.
My observations have shown COLD PSI today isn't the same tomorrow given any weather swings. SO today you set Cold to 70PSI, a few days later it's sitting at 73PSI....going even higher as it heats up while driving. NOT a good idea at all.
I know we hate the way we need to manage tire PSI especially with a loaded bed or heavy trailer load. We just need to be smarter and safer.

 

[gmbpilot757]

All great info gents! Thanks for your input. I think I’ll try 60F/70R on the drive home tomorrow and see how she does and report back.

 

[Blade420Play🔪🏆]

Drive axle has 6600 on it . 9980 is the tandem axle on the RV. (Dual 6k axles). RAWR on the truck is 7500. That weigh ticket above is with all 6 of us and on our way out of Louisville.

Truck drove really well at 60F/75R on the way down.

This is what I run with my 8k travel trailer. I could run less but the higher pressure keeps my sway to almost zilch running past semis and large open/windy areas/bridges

 

[mrmag00]

When we pull the 5er I run 70psi in the rear and 60psi in the front tows great. Think you fine with your weights, have fun Glamping it’s a great times.

 

[Blade420Play🔪🏆]

We looked for almost 2 years before pulling the trigger. I ran all the numbers 50x and then 50x more ensuring what the truck would legally be within limits with. Now that I know exactly how to run the numbers and know what rigs can legally be paired with a SRW F350, I am absolutely amazed and the number of folks I see towing rigs with a F250 or SRW F350 that I know with 100% certainty are over payload by a mile.

I’ve asked folks in th past what they’re running for a pin weight and just get the deer in the headlight look. They have absolutely no idea what pin weight even is. SMH…

Bro, the camper salesman told me my truck could handle it

 

[The Evil Twin]

Thanks I had never heard the 20% rule. My issue is that 65 psi is maximum listed for the Mickey Thompsons I have the Tremor. So I was already at cold pressure maximum when I headed out.
Should I go ahead overfill to 70 (above the limit) or live with the increase in pressure as I drive ( I should note this increase was seen on an 18 hour drive over the Canadian Rocky Mountains).

Like HA said, don’t overinflate.
What is the load index on those tires? 126? The max inflation seems low.

 

[JoeCO]

Bro, the camper salesman told me my truck could handle it

Famous last words!

 

[LWS]

I have the MT Baja Boss LT305/70R18, I was going to go with the 295s due to the increased load capacity, but these were back ordered. The 305/70R18, have a E rating (126Q) at 3750 lbs @65psi. Whereas the LT295/70R18, are E rated (129Q) at 4080 lbs at 80psi.