Recommendations for Air Pressure and Highway Speeds on a 4.80-8 and 5.70-8 Trailer Tire

Updated 07/25/2011 | Published 07/23/2011

Question:

I recently purchased a small luggage trailer to tow behind my Corvette. Total weight of the trailer is 141 lbs. Im thinking packed with luggage it will never weigh more than 300 lbs. It came with 4.80-8 tires/wheels. Recommend air pressure is 60 PSI. With this PSI only about 1 of tread is actually making contact with the pavement. Will it be safe to reduce the pressure to maybe 35-40 PSI? Also, will it be safe to tow at freeway speeds of 70-75 MPH? If not, if I purchase a pair of AM10010 5.70-8 could I achive freeway speeds and lower air pressure? Thanks!

asked by: Lynn J

Expert Reply:

I would always recommend to inflate the air pressure on the trailer tires to the psi that is indicated on the sidewall of the tire. If you reduce the air pressure you will be reducing the weight that the tire will be able to carry. Trailer tires are rated for maximum load and should be inflated as instructed on the sidewall.

When the trailer manufacturer designs that trailer they choose a tire size and load range that can handle the maximum weight capacity of that trailer.

All trailer tires will have a maximum speed rating of 65 miles per hour, unless stated otherwise on the tires. It is not recommended to run a trailer tire at a higher speed than 65 miles per hour due to the heat buildup that will occur inside the tire and cause the tire to break down and cause the tire to fail.

Changing the size of the trailer tire will not change the maximum speed rating on the highway or allow you to lower the air pressure.

I am including a link to a FAQ on trailer tire information.

expert reply by: Jeff D