37X12.50R17LT Tire Size

All You Need to Know About 37X12.50R17LT Tires

A 37X12.50R17LT tire is a Light Truck service-rated radial flotation tire with a nominal 37-inch overall diameter, a 12.5-inch section width, and a 17-inch wheel diameter. The "LT" suffix position - appearing after the wheel diameter - identifies a tire that meets Light Truck construction standards for load capacity, casing strength, and inflation pressure capability.

This article covers 37X12.50R17LT as a suffix-designated LT tire; for prefix-designated LT37X12.50R17 tires, which share the same physical dimensions but carry additional service context in their designation, see the LT37X12.50R17 article.

37X12.50R17LT Size Quick Specs

• Service category: Light Truck (LT) - suffix position
• Nominal overall diameter: ~37 inches
• Nominal section width: ~12.5 inches
• Construction: Radial
• Wheel diameter: 17 inches
• Typical load ranges available: D, E (Load Range C exists but is uncommon at this diameter)
• Recommended wheel width range: 8.5–11.0 inches

Recommended 37X12.50R17LT Tires

What 37X12.50R17LT Means

• 37 = nominal tire diameter in inches
• X = flotation size format separator
• 12.50 = nominal section width in inches
• R = radial construction
• 17 = wheel diameter in inches
• LT = Light Truck service designation, suffix position

The suffix LT in 37X12.50R17LT identifies how the tire is rated after its dimensional and construction information. This suffix convention is used by many manufacturers to indicate that the tire meets LT service standards, as distinct from a standard (non-LT) 37X12.50R17. The distinction between suffix-LT (37X12.50R17LT) and prefix-LT (LT37X12.50R17) is addressed in detail in the LT37X12.50R17 article.

How LT Construction Changes a 37X12.50R17LT vs Standard 37X12.50R17

A 37X12.50R17LT is not simply a heavier version of the 37X12.50R17. The LT designation changes the tire's entire service envelope:

• Load capacity: A 37X12.50R17LT carries a higher rated load at a given inflation pressure than a standard 37X12.50R17 of the same nominal size
• Inflation range: A 37X12.50R17LT is engineered to operate at higher inflation pressures than a standard 37X12.50R17
• Casing strength: The 37X12.50R17LT uses a reinforced casing with additional ply layers compared with the standard 37X12.50R17
• Sidewall puncture resistance: The 37X12.50R17LT's thicker sidewall construction resists trail damage and sidewall punctures more effectively than a standard 37X12.50R17
• Ride firmness: A 37X12.50R17LT rides firmer than a standard 37X12.50R17 at equivalent inflation pressures due to its stiffer casing

Load Ranges Available in 37X12.50R17LT

Load Range D and Load Range E are the most common designations found on 37X12.50R17LT tires in production. Load Range E 37X12.50R17LT tires are rated to 80 PSI maximum cold inflation pressure and carry the highest load capacity within the 37X12.50R17LT size. Load Range D 37X12.50R17LT tires operate at 65 PSI maximum and offer a balance between load support and ride quality. Load Range C exists in LT sizing generally, but is uncommon at the 37X12.50R17LT diameter; most manufacturers producing 37-inch LT tires focus on Load Range D and E.

Who Should Use 37X12.50R17LT

The 37X12.50R17LT is the appropriate choice when a 37-inch flotation tire must also carry a significant load. Typical applications include:

• Trucks that tow trailers with a 37-inch tire fitment
• Diesel trucks or heavy payload trucks running 37X12.50R17LT for load support
• Overland builds carrying roof tents, overlanding gear, and cargo that approach or reach the vehicle's payload rating
• Vehicles where sidewall durability on rocky trails is a priority, alongside load-carrying

A standard 37X12.50R17 without LT construction is not engineered for the load and inflation pressures that a 37X12.50R17LT handles safely.