Tires can lose about 1 to 3 psi (pounds per square inch) of air pressure per month, translating to as much as 9 psi over three months. It might not sound like much. But trailer tires (bearing an ST designation), unlike passenger-car tires, are designed to operate at the maximum-rated psi, which you will find embossed on the sidewall, to maintain their load-carrying capacity. Underinflated trailer tires can also suffer sidewall damage and blowouts on the highway. Check your boat-trailer tires regularly with a quality tire-pressure gauge. Do it before you head out; the ratings are based on “cold psi,” which means the pressure before the air inside heats up from road use. Add pressure as needed.
Keep Your Boat Trailer Tires Properly Inflated
Make sure boat trailer tires are inflated to maximum PSI.