Is It Safe To Mix Load Ranges on Tires and Does It Cause Excessive Vibration

Question:

Recently, a local tire dealer replaced my marathons with Carlisle Trail HD 225/75R15 tires. I noticed that the road noise is excessive when towing this boat trailer as compared with my other boat trailer. I had replaced the drum brakes and bearing kits with you in 2016. After inspection, I noticed one tire is class D and the other is class E. The tires are a perfect match except for the load range. Both tires are 65# cold inflation, the match for the D rating. I am currently replacing bearings and races again because they show excessive wear. I guess probably less than 1,000 miles since I replaced bearings but it has been 3 winters. The E rating says 80# inflation. Currently, both tires are inflated to 65#. Can the tires be my problem to the noise vibration? My local marine dealer doesnt think so and that is why I am replacing bearings again. Thank you for any input, FN

asked by: Fred J

Expert Reply:

Running two different load rated tires can cause a lot of stress on the tires of your trailer and uneven tire wear. We always recommend to inflate tires to their max PSI to avoid heat build up. If you are running both tires at the lower PSI it is causing more wear on the load range E tires that are designed to be inflated to 80 max PSI.

I cannot say for sure that having mixed load ranges on your trailer is causing vibration however if one tire is larger than the other it is definitely going to cause excessive tire wear that could lead to a blow out. The vibration could be caused from exceeding the tire speed rating which is usually stamped on the wall of the tire. You may also consider checking the suspension components on your trailer. You want to make sure nothing is bent or broken. Make sure the holes in the shackle straps are not oval shaped from suspension wear. These components would need to be replaced.

The trailer may also have a bent axle that is causing vibration, I recommend measuring from a single point on the trailer coupler to the center of the axle on one side. Then do the same thing on the other side. You should have identical measurements. If you don't, the axle may be bent which is causing vibration but first I would change the load range D tire out for load range E and see if that fixes your issue.

expert reply by: Heather A