37x13.50R18LT D Nitto Mud Grappler BLK SW37X13. 50R18LT NITTO MUD GRAPPLER MUD TERRAIN 37135018 TIRES Brand: Nitto Model: Mud Grappler Size: 37x13. 50R18LT Part#: 200 660 Aspect Ratio: 13. 5 Inflated Diameter: 37. 05 Inflated Width: 14. 17 Load Index: 124 Load Rating: D Load Range: 3525 LBS Max Load Max Psi: 50 Ply: 8 Revs Per Mile: 733 Section Width: 37 Service Description: 124P Sidewall: Black Speed Rating: P Tire Rim Diameter: 18 Tire Type: Mud Terrain Tread Depth: 21 Weight: 89. 85 lbs