LT on a tire: LT-metric (light truck)
Built for light truck duty, and rated for it without any derating.
What it changes
An LT tire carries a load range letter and is rated at higher inflation pressures than a passenger tire of the same nominal size. It takes no 1.10 derating on a light truck, because light truck duty is what it was rated for. LT tires often print two load indices for single and dual fitment.
Where it sits: Immediately before the section width, or after the size on flotation sizes (33x12.50R15LT).
Two load indices
An LT tire fitted in duals carries 9 percent less than it does singly, to account for the effect of road crown on a twinned pair. That is why a dual-rated tire prints two load indices, for example LT235/85R16 120/116S: 120 singly, 116 in duals. Read the second index off the load index table rather than applying the percentage yourself - the printed pair is the rating.
Sizes in this reference with an LT prefix
Questions
- What does LT mean on a tire?
- Built for light truck duty, and rated for it without any derating. An LT tire carries a load range letter and is rated at higher inflation pressures than a passenger tire of the same nominal size. It takes no 1.10 derating on a light truck, because light truck duty is what it was rated for. LT tires often print two load indices for single and dual fitment.
- Where does the LT appear on the sidewall?
- Immediately before the section width, or after the size on flotation sizes (33x12.50R15LT).
- Does a LT tire take the 1.10 light truck derating?
- No. The 1.10 factor applies to P-metric and Euro-metric tires fitted to a light truck. An LT tire is already rated for that duty.
Where these figures come from
Published values here were read from 4 independent sources:
- Tire code - Wikipedia, revision read 27 August 2026 (read 2026-08-27)Service type letters, construction letters, load range letters and ply ratings, sidewall marking glossary
- Application of Load Inflation Tables, version 20170203 - Nitto Tire (Toyo Tire group) technical bulletin, version 20170203 (read 2026-08-27)P-metric against ISO/Euro-metric load tables, the light truck derating factor, dual fitment reduction, standard load against reinforced
- Load Index & Weight Ratings - rimlist, undated reference article (read 2026-08-27)LT against P-metric fitment, ST trailer tires, SL, XL and HL reference pressures
- Tire Load Ranges: Complete Guide (B Through F) - TireGrades, updated 24 June 2026 (read 2026-08-27)Load range letters with ply rating equivalents and maximum inflation, LT against passenger designations
These are independent publishers, not independent measurements. Each one reproduces a table originally set by a standards body, so agreement between them shows a value was transcribed correctly, not that the underlying table is right. Where a figure is safety relevant, check it against the tire manufacturer's own data before relying on it.