Glossary

Single tire

Last reviewed: 2026-05-20

A tire used alone on a wheel end rather than paired with a second tire as a dual assembly. Steer axle positions on a standard highway tractor are almost always single-tire service. Wide-base single tires also replace dual assemblies on drive and trailer positions in some fuel-optimized configurations. The load rating for a tire in single service is typically higher than the same tire's dual service rating — in single service the tire has better heat dissipation and is not affected by load-sharing inconsistencies from a mismatched dual mate. Always use the single-position rated capacity from the manufacturer's table when the tire is used alone.

Use the single rated capacity for steer tires and wide-base singles, and use the dual rated capacity for any tire in a dual assembly. Using the single rating for a tire in dual service overstates what the tire can carry — by potentially hundreds of pounds per tire — and may lead to overloading the assembly without a visible indicator. When a tire is converted from a single to a dual position (or vice versa), always recheck the applicable load rating from the manufacturer's table for the new configuration before approving the installation.

Real-World Use

A shop technician checking a replacement drive tire uses the dual-position rating from the manufacturer's data sheet rather than the single rating — the dual rating is lower because of heat and load-sharing conditions in dual service. Later, the technician is asked about temporarily substituting a drive tire in a steer position. The substitution requires checking whether the tire is approved for steer use and which rating applies — steer positions use the single rating. A tire with adequate dual capacity may or may not have adequate single-position capacity; the manufacturer's table for the specific tire resolves the question.

What to Pair It With

Read this term with the full tire sidewall, vehicle rating information, manufacturer documentation, and the actual condition of the tire.

This site is for general information only. It does not replace professional tire service, DOT compliance advice, tire manufacturer instructions, vehicle manufacturer recommendations, or fleet policy.