Factory Gen 2 and Gen 3 base Raptors run 315/70R17 (equivalent to 35x12.5) BFGoodrich KO2s on 17x8.5 wheels. 37s on a Gen 3 require the factory 37 Package or a leveling kit plus minor clearance work.
The Raptor was designed around large tires from day one. Gen 1 SVT ran 315/70R17 BFG All-Terrain T/A KO. Gen 2 moved to the KO2 in the same size. Gen 3 base continues with 315/70R17, and the optional 37 Package steps up to 37x12.5R17.
The SVT Raptor came from the factory on 315/70R17 BFG All-Terrain T/A KO (later KO2) tires on 17x8.5-inch forged aluminum wheels. This is equivalent to approximately 34.4" tall — commonly rounded to 35" in conversation.
Tire swaps on Gen 1: any 315/70R17 fits without modification. Moving to a true 35x12.5R17 adds a small amount of height (roughly 34.4" vs 35.0") — clearance is fine at full stuff with stock suspension in good condition. Rubbing at full lock-to-lock articulation is possible depending on the specific tire brand's width. Test before finalizing.
Same baseline as Gen 1 in concept, upgraded tire. The 315/70R17 KO2 is the OEM tire and the correct size for stock suspension. In practice, the Gen 2's suspension geometry was designed around this tire — it clears at full compression and full articulation.
Running true 35x12.5 (slightly taller and wider depending on brand): most 35x12.5R17 tires fit without modification, but the extra section width can cause contact at full compression depending on the tire brand's actual measured width. BFG's 315/70R17 is actually 12.4" wide; a 35x12.5 from another brand may be slightly wider and may require minor fender liner trimming.
**Running 37s on a Gen 2:** A leveling kit (typically 1.5"–2") creates enough clearance for 37x12.5R17 tires at full stuff. However, the factory 3.73 gear ratio becomes noticeably strained with 37s. Performance degrades meaningfully — acceleration, throttle response, and highway cruise RPM all shift unfavorably. If running 37s on a Gen 2, regearing to 4.10 or 4.56 is the right call.
The Gen 3 diverged into two tire specifications:
**Base Gen 3:** 315/70R17 BFG KO2 — same as Gen 2, no changes in fitment behavior.
**37 Package (optional):** 37x12.5R17 BFG KO2 on 17x8.5 forged beadlock-capable wheels, paired with 4.10 axle gears and upgraded Brembo brakes. This is a factory-engineered package — Ford sized the fenders, calibrated the ABS, and chose the gears specifically for 37s. It is not an afterthought.
Running 37s on a non-37-Package Gen 3: technically possible with a leveling kit, but you're missing the 4.10 gears that make the truck functional with the taller tires. The non-37-Package Gen 3 has 3.73 gears — the same penalty as Gen 2 with 37s.
At full suspension compression (both wheels droop), the Raptor's long-travel suspension moves the tire significantly upward relative to the body. Factory 315/70R17 clears in all four corners without issue. The concern zone is the front at full compression combined with full steering lock. On stock suspension with stock 315/70R17, clearance is designed in. Adding width (wider tire brand) or height (37s without a leveling kit) changes this.
A practical test: with the truck on flat ground, turn the wheel to full lock in both directions and bounce the front of the truck manually. If it rubs, you need more clearance before going off-road where actual full-compression events will happen.
| Part | Vendor | Est. price |
|---|---|---|
| BFGoodrich KO2 35x12.50R17 | BFGoodrich | ~$350 |
| BFGoodrich KO2 37x12.50R17 | BFGoodrich | ~$390 |
| Toyo Open Country AT III 35x12.50R17 | Toyo | ~$320 |
Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.