Best Tire Pressure for Westlake Trailer Tire?

Updated 08/06/2019 | Published 08/03/2019

Question:

Hi. Ive got a boat trailer just two tires and cant find out the best PSI for inflation of Goodyear Endurance ST205/75R15 tires. The total boat-and-motor weight is 2100-2300 lbs., and I believe the tires inflate up to 65 lbs max. Can you suggest a smart PSI that wont let sidewalls suffer from under-inflation, but also avoid too bouncy a ride? Thanks for any advice you can give!

asked by: Evan S

Helpful Expert Reply:

The Goodyear Endurance ST205/75R15 tire and wheel combo # LH53FR is a great tire and wheel combo because as the psi used in the tire goes up, the weight capacity of the tire goes up and vice versa; this requires you to use a lower tire pressure when you're not carrying the maximum recommended load of the tires in order to get the best performance. With a Load Rating of D, these tires are rated for up to 2,150-lbs per tire (total of 4,300-lbs on a single axle trailer) and should be filled when cold to 65 psi for carrying the max load. However, as the weight of the towing load goes down, they require less air pressure.

Keeping this in mind and using the Goodyear Endurance chart that I'm attaching to this question, your boat and trailer are likely going to weigh between 2300-2600-lbs. Using that weight, the recommended psi for the best handling and ride at that weight will be between 25-30 psi. You should confirm to the total weight of your trailer and boat fully loaded in order to determine if there is any difference between my estimate and the actual weight.

expert reply by: Erik B