E vs. D rated trailer tires

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.

I get the same thing in my Excursion. I have 1 ton rear overload springs and with tires at 80 psi it rides great towing our camper. However, after unhooking and driving around 'empty' it is like a dumptruck.

Tire/wheel size and load rating (D obviously, but weight rating) and camper weight needed to make any accurate recommendation.

time2roll wrote:
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.

I agree on the ENDURANCE.

Bottom line know what each axle and preferably what each tire is carrying. If the "D" tire has plant of capacity for your weight then stick with "D" but if close to the MAX rating buy the "E" and run them at the same pressure as the "D" tires required. Better yet use the load inflation chart for the "E" and add 5 psi to what the chart dictates.

My Boat Trailer had "C" tires in 14" and I changed to "D" ENDURANCE and guess what the "C" inflation of 50psi was correct for the new "D" tires. 20k with plenty of tread left and wearing perfectly even.

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

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.