Sorry for the long post but I am looking for input. We had a Passport 24ft, loaded on a 1500 mile trip last summer.
CAT scale was 4060 on the trailer, GCW was 10,400lbs. Winter came and I replaced the OEM Goodyear Wranglers with Michelin Defenders LTX, 275/55/20.
Spring came and we took a trip with the same trailer, and I could not keep it on the road. Felt like I was riding on marshmallows.
We upgrade the WDH to a Curt TruTrac and solved it for the whole summer, 7 trips.
The wife wanted a bigger RV, KZ C211, 26ft.GVW empty of 4460lbs. We took it on a 8 day trip and the marshmallow felling is back.
I am under on the axle weights and gross combined weights, but driving is a real challenge.
Have the Timbrens already and Bilstein 4600 shocks.
GCVW 12,700 per Ford site.
CAT Scale was at 11,380 so I am heavier than we will ever be.
All of the handling problems started with the Michelins, they are SL rated tires from Big O Tires.
Max air pressure of 44PSI and load of 2535lbs.
Been looking at the BFG KO2 tires..
Why would I need E rated tires on a truck that cant haul that much anyway?

thanks

 

We pull a 26' (box) 30' overall Passport with similar weights on Cooper AT3 117 rated tires in same size 275/55/20 and run the same pressures. It tows fine over the past 3000 miles.
2020, 3.5eco, 4point EQ hitch.

 

I see you saying the max air pressure, but I don't see you saying what air pressure you have in them.

 

Yeah run 40psi and possibly upgrade to a 117 if that doesn’t work.

I wouldn’t mess with the ride and mpg going to an aggressive AT in E.

You also should check your trailer axles and balance and rotate the tires on it.

 

Non-light truck tires seem to Tow best set at maximum sidewall pressure. Lessens the radial side to side roll so smaller movements of the trailer tongue don't waggle the truck much.

 

I started at the OEM of 35PSI, then went to max of 44PSI,
scary ride to TX and contact Michelin, they told me to drop it to 38PSI. no change

 

As I have started learning more about tires I have figured out that most tire shops are clueless about tires really.
They know how to sell them and I think this group knows more than the salemen do.
Mine are rated at 113

 

Have you checked over your trailer? Axles and balance rotate the tires?

Is this michelin tire the same height as the stock ones? No changes with the hitch? Shocks are still good on the truck (doesn’t bounce around unloaded)?

Those 44psi 113 tires are rated the same as the factory tires. They said 38psi so you don’t heat them up past the max I bet.


Last but least. Rotate and balance them. I think 40psi is safe. We run a 110 at 40psi loaded all the time and it wears like its overloaded but doesn’t heat up past 44psi. Not overloaded per the payload though but hovering around it.


These factory tires are on the weak side.

 

I would agree that the numbers all look good, but the handling issues started with the Michelins. OEM Goodyears pulled the first trailer at 35 PSI with no problems.
Tire shop did a road force balance on these and found no problems.
But these will not carry weight at any PSI.
Frustrating