LT vs P-metric tires
P-metric tires are made mainly for passenger vehicles. LT (light truck) tires are rated with load range letters instead of standard and extra load, and carry their rated load at higher pressures.[1 · Oct 29, 2026][2 · Oct 29, 2026][3 · Oct 29, 2026]
LT load ranges
| Load range | Ply rating | Max load pressure |
|---|---|---|
| B | 4 | 35 psi |
| C | 6 | 50 psi |
| D | 8 | 65 psi |
| E | 10 | 80 psi |
| F | 12 | 95 psi |
Tire Rack lists lower maximum pressures for some wide sizes and notes the ply rating describes strength, not the actual number of plies.[2 · Oct 29, 2026]
Why LT tires need more air
An LT tire only carries its rated load at the pressure that goes with it. Toyo warns that LT tires run underinflated for the load build up heat, which leads to fatigue and failure. Its example: an LT245/75R16 Load Range C, D or E all need 50 psi to carry what a P245/75R16 109 carries at 35 psi.[3 · Oct 29, 2026] Toyo also notes the higher pressure makes for a harsher ride.[3 · Oct 29, 2026]
To find the equivalent, Toyo says to look up the original tire's load at the placard pressure in the Tire and Rim Association load tables, then use the light truck table to find the pressure that gives the same load.[3 · Oct 29, 2026] A tire professional can do this for you.
P-metric tires on light trucks
When a light truck or SUV comes with P-metric tires, federal rules (FMVSS 571.120) have the vehicle maker reduce the tires' rated load by a factor of 1.10. Toyo's example: 2,271 lb ÷ 1.10 = about 2,065 lb at 35 psi.[3 · Oct 29, 2026] If you replace original LT tires with P-metric tires, check the load carefully, because P-metric tires often don't have enough capacity.[3 · Oct 29, 2026]
Quick comparison
| P-metric | LT | |
|---|---|---|
| Marked | P before the size (or no letter for Euro-metric) | LT before the size, or LT after a flotation size |
| Load rating | Standard Load or Extra Load | Load range B to F |
| Max load pressure | 35 to 42 psi | 35 to 95 psi by load range |
| Dual load index | No | Often, such as 104/101 |
Table summarized from the Tire Industry Association and Tire Rack pages cited below.[1 · Oct 29, 2026][2 · Oct 29, 2026][4 · Oct 29, 2026]
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Sources: 1. Tire Industry Association, Reading a tire sidewall. 2. Tire Rack, What are load ranges and ply ratings?. 3. Toyo Tires, Technical bulletin TSD-12-011: Replacing tires on light trucks (PDF, Aug 2012). 4. Tire Rack, What is load index?. Checked Oct 29, 2026. Size dimensions, revolutions per mile and speedometer figures are our own arithmetic from the size code. Trademarks belong to their owners; figures are restated in our own words and tables, not reproduced.