37-inch tires are a serious commitment. They transform your truck into a trail monster but require significant modifications beyond just a lift kit. Here is everything you need to know before pulling the trigger at American Fusion Wheels.
37" Tire Specs
Sizes: 37x12.50R17, 37x13.50R17, or 37x12.50R20. Actual diameter is 36.7" to 37.2". Weight is 70-90 lbs per tire — significantly heavier than 35s (50-65 lbs).
What You NEED to Run 37s
- 6"+ suspension lift — a 4" lift will not provide enough clearance
- Regearing to 4.88 or 5.13 — mandatory, not optional. Without regears, your truck will feel sluggish and your transmission will overheat towing or climbing
- Extended brake lines — factory lines are too short
- Extended bump stops — prevent tire contact during full compression
- Fender trimming or flat fenders — significant rubbing at full lock
- Heavy-duty ball joints and tie rods — factory parts wear fast with 37s
- Upgraded brakes — stock brakes struggle to stop the extra rotational mass
Pros of 37-Inch Tires
- Massive ground clearance — climb anything
- Dominant look — there is nothing else like it
- Serious rock crawling capability
- Highest fording depth for water crossings
Cons of 37-Inch Tires
- Expensive — $350-$600 per tire
- 3-5 MPG decrease
- Limited tire selection — fewer options than 33s or 35s
- Total build cost is $8,000-$15,000+ with all required modifications
- Daily driving is challenging — parking, turning radius, tight spaces
Best 37-Inch Tires
- Nitto Trail Grappler MT 37x12.50R17 — ~$450. Best MT for 37s, great trail performance.
- BFGoodrich KM3 37x12.50R17 — ~$470. Toughest sidewalls in the business.
- Toyo Open Country MT 37x13.50R17 — ~$490. Premium build quality.
- Mickey Thompson Baja Pro XS 37x13.50R17 — ~$500. Race-bred MT.
Who Should Run 37s?
Yes, run 37s if: You are building a dedicated trail rig, rock crawler, or overland truck. You regularly hit serious off-road terrain. You have the budget for a complete build ($8K-$15K+).
No, do not run 37s if: You want a daily driver. You are not willing to regear. You want budget-friendly. Stick with 35s.
Call (913) 291-2027 — we design complete 37" builds with regears and proper supporting mods. | Off-Road Builds