Most tire codes begin with one or two letters to identify the type of vehicle and/or type of service the tire was designed for. The example shown and explained below is P195/60R15 87H
P - A tire size beginning with "P" indicates the tire was designed for use primarily on passenger vehicles. This however includes use on minivans, smaller sport utility vehicles and light trucks as well as cars. Cargo vehicles using "P" coded tires are of 1/2 ton load capacity or less.
LT - A tire size beginning with "LT" indicates the tire was designed for light trucks. LT tires are used on vehicles capable of carrying cargo or towing a trailer. These are typically used on 3/4 to 1 ton load capacity pickup trucks, sport utility vehicles and full size vans.
(Example: LT245/75R16 108/104S)
T - A tire size beginning with "T" indicates the tire was designed for TEMPORARY use as a spare. These are space saving mini spares that may only be used briefly until a failed tire is replaced.
ST - A tire size beginning with "ST" indicates the tire is for special trailer service and designed for use on a boat or utility trailers. ST tires are not suitable for use on cars, vans or trucks.
(Example: ST225/75/R15)
None - Absence for a letter preceding the numeric portion of a tire size indicates a "Euro-metric" size. Primarily used on European cars, they are used on vans and sport utility vehicles too. These tires are equivalent to "P" coded tires but may differ slightly in load carrying capacity.
Ending C - A Euro-metric tire ending in "C" indicates the tire was designed for use on light commercial vehicles. "C" coded tires also carry a Load Range rating of B, C, or D.
Ending LT - A tire size ending with "LT" indicates the tire is a wide base or flotation Light Truck tire for vehicles carrying cargo or towing trailers. These fit 16.5 inch rims or larger. Wide base or flotation tires help the vehicle on loose or sandy driving surfaces. These tires are used on 1/2, 3/4 and 1 ton load capacity pickup trucks and sport utility vehicles.
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