The 37x12.50R18LT Nitto Trail Grappler M/T is a load-range E mud-terrain tire with a 128Q service description. Its tread layout is designed for trail use while addressing the noise that matters on the drive to and from the trail.
Published dimensions are 36.77 inches in diameter and 12.52 inches in inflated width on a measuring rim 10 inches wide; approved wheel widths run from 8 to 10.5 inches. New tread depth is listed at 21/32 inch. Reinforced three-ply sidewalls support the design on this size. Two sidewall appearances let you choose between stylized lettering with V-shaped lugs and traditional lettering with flatter buttresses.
The maximum single-tire load is 3,970 lb at 65 psi. Match the size, wheel dimensions, load and speed requirements to your vehicle, then have a qualified installer check steering and suspension clearance. Published dimensions are a planning reference, not a vehicle-specific fitment guarantee; maximum pressure is not the recommended operating pressure.