We are moving back to WI after 4 years of living in Miami and I'm making my list of items to address since my unit is 5 years old. One of those is tires. I still have the stock 'Trailer King" D rated tires, and will be changing them out. What exactly is the rationale behind going to an 'E' rated tire on a camper? Obviously more load carrying capacity I understand, but does it ride harder then too? I certainly don't need more jarring transmitted to the chassis. I feel like if you need the load carrying capabilities of a higher rated tire you might also be overloading the chassis. Is it just higher quality of tire? Kind of like going to an 'F' when an 'E' will do the job more comfortably. Is it just peace of mind / bragging rights?

In many cases the OEM supplied tires are just barely sufficient, for the trailer at full GVWR. They even take into consideration, that some of the wt will be carried by the hitch.If D-rated tires are adequate for your trailer wt on the axles, then no need to go to E-rated. If your current tires are at the edge of needed rating, then moving up may be a good idea.Jerry

Some people have moved from D-rated ST tires to E-rated LT tires due to the better, IMO, construction of the LT tires. But you need to move up a rating to get the carrying capacity.

You will need to do some math. Look at the sidewall of your current tires for max weight capacity. It will look something like 2500 @ 60 max inflation. Take the Max number times the number of tires. In the example above 2500 x 4 = 10,000 lbs. If your trailer GVWR is less than the total amount you don't need a higher rated tire. If you do go to a higher rated tire you most likely would not need to run them at maximum pressure. There are tire pressure charts out there from most reputable tire manufacturers so you can match the pressure to the weight of the trailer. This would reduce some of the bounce.

schlep1967 wrote:You will need to do some math. Look at the sidewall of your current tires for max weight capacity. It will look something like 2500 @ 60 max inflation. Take the Max number times the number of tires. In the example above 2500 x 4 = 10,000 lbs. If your trailer GVWR is less than the total amount you don't need a higher rated tire. One thing missing from the above is the hitch weight isn't riding on the tires.A 12k GVWR 5th wheel with 2500lb on the pin, is fine with 2500lb tires. as there will be at most 9500lb on the 4 tires (assuming you don't exceed GVWR).Moving up one notch on the tire ratings, is generally going to be fairly harmless. Jumping up multiple notches will do exactly what the OP is concerned about. There's going to be very little give in the tire and that will transfer to the suspension, frame and rest of the trailer. To give you an idea: If you've ever rode in a 3/4 or 1 ton pickup that's empty. The ride is very jarring over bumps (tires/suspension are very firm). Load up 1500-2000lb in the back and the ride smooths out a lot because the tires and suspension are absorbing rather than transmitting the forces.

Get the GY Endurance tires. Probably E rated depending on size. If the ride is bad at 80psi then drop it down to 70-75 psi. But I think it will ride better not worse. Higher margin of load rating will reduce the chance of tire failure. Most factory tires are very close to max rating and is part of the reason people have tire failures.

E vs. D rated trailer tires | Good Sam Community

phillyg
Explorer II
Jun 14, 2022
It probably won't ride harder if you adjust your psi downwards, based on your actual weight, and using the tire mfgrs. load table. And, congrats on getting 5 years on Trailer Kings, most fail well before then.
Cummins12V98
Explorer III
Jun 15, 2022
2112 wrote:
I had Ds on my FW and kept them aired up to 65psi. I upgraded to Endurance Es and air then up to 68psi.

I tried then at 75psi and it was like the FW was riding on basketballs. Aired them down to 68 and now it rides smooth as glass.

The load chart was about 55psi for my weight

Nice seeing a Man using the brain God gave him.
Cummins12V98
Explorer III
Jun 15, 2022
theoldwizard1 wrote:
Forget ST tires. Use LT tires. Many more brands and sizes to choose from.

Letter and ply rating are "old school" and should not be trusted. Use the actual weight rating on the sidewall. It will also tell you the correct pressure.

Correct pressure for what???
theoldwizard1
Explorer II
Jun 15, 2022
Cummins12V98 wrote:
theoldwizard1 wrote:
Forget ST tires. Use LT tires. Many more brands and sizes to choose from.

Letter and ply rating are "old school" and should not be trusted. Use the actual weight rating on the sidewall. It will also tell you the correct pressure.

Correct pressure for what???

Correct pressure for the rated load.
CapriRacer
Explorer II
Jun 15, 2022
I see no one has mentioned that a Load Range E has the same load carrying capacity as a Load Range D when inflated to the same pressure. At the LR D pressure, a LR E performs the same - ride, sway, etc.

So you can buy a LR E and use it in place of a LR D.
2112
Explorer II
Jun 15, 2022
It was a pease of mind for me. One less thing to worry about.

CapriRacer wrote:
I see no one has mentioned that a Load Range E has the same load carrying capacity as a Load Range D when inflated to the same pressure. At the LR D pressure, a LR E performs the same - ride, sway, etc.

So you can buy a LR E and use it in place of a LR D.
Actually they have about 18% more capacity when inflated to the same pressure when comparing the 75R15(D) and 75R15(E).

Endurance Load Chart

I have 8400lbs across 4 tires. So according to the chart I should air them to 50psi. Even at 55psi they looked too low and would have too much sidewall flex. 68psi just looks and feels right to me. YMMV
Cummins12V98
Explorer III
Jun 15, 2022
theoldwizard1 wrote:
Cummins12V98 wrote:
theoldwizard1 wrote:
Forget ST tires. Use LT tires. Many more brands and sizes to choose from.

Letter and ply rating are "old school" and should not be trusted. Use the actual weight rating on the sidewall. It will also tell you the correct pressure.

Correct pressure for what???

Correct pressure for the rated load.

Thought for a minute you were a fill it to MAX psi no matter what kinda guy.
Cummins12V98
Explorer III
Jun 15, 2022
CapriRacer said: "I see no one has mentioned that a Load Range E has the same load carrying capacity as a Load Range D when inflated to the same pressure."

I kinda did say it in code: "but if close to the MAX rating buy the "E" and run them at the same pressure as the "D" tires required."
Cummins12V98
Explorer III
Jun 15, 2022
2112 wrote:
It was a pease of mind for me. One less thing to worry about.

CapriRacer wrote:
I see no one has mentioned that a Load Range E has the same load carrying capacity as a Load Range D when inflated to the same pressure. At the LR D pressure, a LR E performs the same - ride, sway, etc.

So you can buy a LR E and use it in place of a LR D.
Actually they have about 18% more capacity when inflated to the same pressure when comparing the 75R15(D) and 75R15(E).

Endurance Load Chart

I have 8400lbs across 4 tires. So according to the chart I should air them to 50psi. Even at 55psi they looked too low and would have too much sidewall flex. 68psi just looks and feels right to me. YMMV

My Endurance on my Boat Trailer "LOOK" low but the proof is in the pudding they are right on at 50psi as the tread is perfectly even at 20,000 miles.
Grit_dog
Navigator
Jun 15, 2022
theoldwizard1 wrote:
Forget ST tires. Use LT tires. Many more brands and sizes to choose from.

Letter and ply rating are "old school" and should not be trusted. Use the actual weight rating on the sidewall. It will also tell you the correct pressure.

Speculation on what the OP even has or needs, on your part....and everyone else who has drug this out 2 pages now, beginning to argue about it and the OP hasn't even given any real info to help someone advise him on his question....
Sheesh....try to focus here.

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