The Lowdown On Tires

By Pat Piper

They're the most important part of your boat trailer.

Tire Wear

Watch for spider cracks that occur from dry rot and uneven tread. If the tire wears in the center, it indicates overinflation, if it wears on the sides, it indicates underinflation.

Many trailer tires have treadwear indicators that will show a different color as the tread becomes worn. Look for the last four digits of the DOT identification stamp on the sidewall of your tire. The first two numbers represent the week in which the tire was made. The second two represent the year. A tire with a DOT code of 1209 was made in the 12th week of 2009 (on some tire brands, this may be on the inside sidewall).

Tire Tips

Try to park your trailer on a hard surface; grassy areas can contribute to corrosion, and accelerate tire rot. Tires are also affected by long-term exposure to the sun, so cover the sidewalls.

Check the valve stem by pushing it to the left and right (gently) to see if air escapes. A leak there can be the reason for low tire pressure.

Two Kinds Of Trailer Tires

Bias Ply:

Less expensive and preferred for shorter trips.


More expensive, but they run cooler and last longer.

Two kinds of Trailer TiresClick to Enlarge Image

FACT: A study by BoatUS Marine Insurance Claims involving boat trailers shows that 39% occurred because the trailers weren't maintained properly.

— Published: Summer 2013

Trailering Magazine is a benefit of BoatUS TRAILER ASSIST®.

BoatUS TRAILER ASSIST® provides:

  • On-the-road assistance for your trailer and vehicle
  • Special edition Trailering magazines
  • $15 coupon (off $100 purchase) for shopping at West Marine
  • Only $38 Annually! ($24 Membership + $14 TRAILER ASSIST)