XL (extra load)

How to read it

FMVSS 139 defines an extra load tire as one designed to operate at higher loads and higher inflation pressure than the corresponding standard tire, and a reinforced tire in almost the same words. Michelin says XL tires have reinforced construction to carry higher loads than standard tires of the same size when inflated to higher pressures, and lists XL and Reinforced together. An XL tire has a higher Load index (95 in 95H) than the standard load (SL) version of its size: Bridgestone’s example is 205/55R16 91 standard load and 94 extra load.

Also searched as: extra load, reinforced, XL tire.

The pressure that goes with it

Bridgestone’s manual gives the pressure at which each version reaches its maximum load: 240 kPa (35 psi) for a P-metric standard load tire and 280 kPa (41 psi) for P-metric extra load; 250 kPa (36 psi) for a Euro-metric standard load tire and 290 kPa (42 psi) for Euro-metric extra load or reinforced. Ford’s manual gives 42 psi (2.9 bar) for extra load, and Yokohama 41/42 psi. The federal high speed test inflates standard load passenger tires to 220 kPa and extra load tires to 260 kPa (FMVSS 139).

More load only at higher pressure

Bridgestone’s manual shows that the extra capacity depends on the pressure. At 240 kPa (35 psi), its 205/55R16 94 extra load tire carries 1,268 lb, less than the 1,312 lb of the 91 standard load version; at 300 kPa (44 psi) the extra load tire carries 1,477 lb, against 1,356 lb. Bridgestone says that for these tires an equal or higher load index can be a poor guide to load capacity.

LL, SL, XL and HL

Yokohama says passenger tires are marked light load (LL), standard load (SL) or extra load (XL). Michelin describes HL (High Load) as a newer designation for heavy electric vehicles, carrying more than an XL tire at the same pressure. Light truck tires use Load range (LOAD RANGE E) letters instead.