Tire Topics – Light Truck & SUV Tires
What is the definition of a Light Truck Tire?
This is not as easy as it sounds. We define a light truck tire as any tire line or size that would typically be applied on a light truck vehicle (SUV, pickup, van). As such, it could be an LT-metric tire for use on a GMC 2500HD or a P-metric ‘light truck’ size of a typical tire line such as the P245/65R17 on a GMC Envoy. Since these vehicles have so many different uses, it makes sense that several tire types are used on them as original equipment to complement specific models.
Types of Light Truck Tires
Since so many Pickups and SUV’s are originally equipped with standard P-metric sized passenger tires it is important to understand the typical construction features that are added with P-Metric sized Light Truck tire designs and Light Truck designs in Light Truck sizes.
Light Truck Numeric:
7.50R16LT
- 7.50 – Section Width in inches
- R – Radial construction
- 16 – Rim diameter in inches
- LT – Light Truck designation
Light Truck High Flotation:
31X10.50R15LT
- 31 – Approx. Tire diameter in inches
- 10.50 – Approx. Section width in inches
- R – Radial construction
- 15 – Rim diameter in inches
- LT – Light Truck designation
Light Truck Metric:
LT265/70R17
- LT – Light Truck designation
- 265 – Section width in millimeters
- 70 – Aspect ratio
- R – Radial construction
- 17 – Rim diameter in inches
Prefix letters such as ‘P’ and ‘LT’ are used as part of tire size designations to differentiate between tires designed primarily for passenger and light truck service conditions.
Definitions (per Tire and Rim Association):
‘P’ Identifies a tire primarily intended for service on passenger cars
‘LT’ Identifies a tire primarily intended for service on light trucks
The load/inflation formulas developed for ‘LT’ designated sizes are different from those for ‘P’ designated sizes due to the more demanding load and service need on light trucks. In order to properly select passenger tires for use on light truck vehicles (mini pick-ups, mini-vans, recreational vehicles, SUV’s, full-sized 1/2 ton.
Ply Rating/Load Range
While there is no industry-wide definition of ply rating, truck tires are frequently marked with ply rating and equivalent Load Range. These markings are used to identify the load and inflation limits of that particular tire, when used in a specific type of service. The table shows the conversion of tire markings.
| Ply | Load |
|---|---|
| Rating | Range |
| 2 | A |
| 4 | B |
| 6 | C |
| 8 | D |
| 10 | E |
| 12 | F |
| Ply | Load |
|---|---|
| Rating | Range |
| 14 | G |
| 16 | H |
| 18 | J |
| 20 | L |
| 22 | M |
| 24 | N |