What does SL ply rating mean on tires?
Reading Tire Load Info. Most alphanumeric tires feature a load range of B, which indicates that they are restricted to the load that can be carried at a maximum inflation pressure of 32 psi. C, D, or E tires are capable of greater loads. Most load range C, D, and E tires are intended for light-truck applications.
Function. Tires are given a maximum load rating based on the tire's size, construction and inflation pressure. P-metric sized tires--tires with sizes starting with a "P" such as P235/75R15--are given a load range rating of either SL or XL. SL stands for Standard Load and XL indicates extra load.
- Light Truck Tires
LT-Metric, LT-Flotation and LT-Numeric Light Truck Tires Load Range Ply Rating Abbreviated D 8 D E 10 E F 12 F
- Passenger Tires feature specific categories, with most falling in the 'standard load' range. Light Load (branded as LL on the sidewall) has a maximum load pressure of 35 PSI. Standard Load (SL or no branding) also has a maximum load pressure of 35 PSI. Extra Load (XL) has a maximum load pressure of 41 PSI.
- Speed Rating V. Once the highest speed rating a tire could have, “V” used to represent a maximum of 149 mph (240 kph) or more. Nowadays, it means 149 mph but no higher.
Updated: 2nd October 2019