This compares each step up using the vehicle makers’ spec sheets, tire makers’ spec tables, published gearing guidance and counted owner reports. See how we research.
Size, weight and speedometer
From maker specs| Step | Real diameter | Weight per tire | True speed at an indicated 60 mph* |
|---|---|---|---|
| 33 in. (LT285/70R17 E) | 32.76 in | 54.6 lb | 60 mph |
| 35 in. (35x12.50R17 E) | 34.53 in | 67.2 lb | About 63 mph |
| 37 in. (37x12.50R17 D) | 36.54 in | 75.6 lb | About 67 mph |
Each step is about 2 inches taller. Counting four tires and a full-size spare, 35s add about 63 lb over 33s, and 37s about 105 lb. Factory 35-inch packages also change the gearing.
What the factories pair with each size
From maker specs| Vehicle | 33 in. | 35 in. | 37 in. |
|---|---|---|---|
| Jeep Wrangler JL (2026) | Rubicon, Willys: LT285/70R17, 4.10 axles | Xtreme 35 package: LT315/70R17, 4.56 axles, 1.5-in. factory lift | – |
| Jeep Gladiator (2026) | Mojave, Rubicon: LT285/70R17, 4.10 axles | – | – |
| Ford Bronco (2026) | Badlands: LT285/70R17 | Sasquatch package: LT315/70R17, 4.70 final drive | Raptor: 37x12.5R17, 4.70 final drive |
| Toyota Tacoma (2026) | TRD Pro, Trailhunter: 265/70R18, 3.583 final drive | – | – |
| Toyota 4Runner (2025) | TRD Off-Road, TRD Pro, Trailhunter: 265/70R18, 3.583 final drive | – | – |
Gearing
Taller tires act like taller gears, so the engine turns slower at the same speed and has less leverage. Jeep goes from 4.10 axles on its 33s to 4.56 on its 35s; Ford uses 4.70 on both its 35s and its 37s. Toyota keeps 3.583 on everything, but offers no 35-inch tire.
Published guidance for 37s on a Jeep ranges from about 4.56 to 4.88 (4 Wheel Parts) to 4.88 or 5.13 (Quadratec). Simply matching a 4.10 Jeep’s gearing to 37s by tire height works out to about 4.57.
Among owners who regeared after going bigger, mostly 3rd-gen Tacoma and 5th-gen 4Runner owners, most chose 4.88 or 5.29 and say the truck drives better. Mileage after regearing ranged from slightly better to about 2 mpg worse. We found no regear data yet for the 2024-and-later Tacoma or 4Runner.
Fuel economy
What owners report From 20 owner reports
- Most report losing 1 to 3 mpg after going up a size.
- The range runs from 1.5 mpg better to about 6 mpg worse.
- The two owners who gained also changed tire model at the same time.
Most of these are dash readings. A speedometer set up for smaller tires reads low, so it also under-counts miles, and the real loss is likely a little smaller than owners see: about 5% better than the dash shows on 35s and about 11% on 37s. Lifts, bumpers and tunes usually change at the same time, too.
Lift
Jeep’s factory 35s come with a 1.5-inch lift. For the Gladiator, 4 Wheel Parts says a Rubicon clears 35x12.50 tires on stock suspension with only minor rubbing on the street, and recommends a 1–2-inch lift for full articulation off-road and 2–3 inches with set bump stops for 37s. Quadratec says Jeep owners fitting 37s should start with at least a 2.5-inch kit. Bronco owners in our log on 37s mostly run a 2–3-inch lift.
See what owners fit without a lift in our Wrangler JL and Tacoma tire guides. Compare any two sizes with the tire size calculator, and check the load rating of a bigger tire in tire load range explained.
FAQ
Do I have to regear for 35s?
Not to make it run, but Jeep and Ford both lower the gearing on their factory 35-inch packages (4.56 and 4.70). Owners on stock gears are split: 7 in our log complain about power, and 6 say they noticed little or no loss. Work out your ratio in regearing for bigger tires.
How much heavier is a 37 than a 33?
On Nitto’s Recon Grappler A/T, about 21 lb per tire: 75.6 lb for the 37x12.50R17 D against 54.6 lb for the LT285/70R17 E.
How far off will my speedometer be?
On a speedometer set up for 33s, about 5% low on 35s and about 11% low on 37s: an indicated 60 mph is about 63 on 35s and about 67 on 37s.
Sources
Show all 38 sources
Manufacturer data (9)
- Stellantis, 2026 Jeep Wrangler specifications
- Stellantis, Jeep Wrangler Xtreme Recon package release (2021)
- Stellantis, 2026 Jeep Gladiator specifications
- Ford, 2026 Bronco technical specifications
- Ford, 2026 Bronco order guide
- Toyota, 2026 Tacoma product information (forum-hosted copy)
- Toyota, 2025 4Runner product information (forum-hosted copy)
- Nitto, Recon Grappler A/T sizes and specs
- Toyo, Open Country A/T III product sheet
Owner reports (25)
- Bronco6G, Regearing and doing 37s right
- Bronco6G, Fuel range with 37's?
- Bronco6G, 37s and MPG from 35s
- Bronco6G, MPG with 35s vs 37s
- Bronco6G, MPG on Bronco with 37 tires
- Bronco6G, 37 tire regrets?
- Bronco6G, Engine power issues with 37's?
- Bronco6G, MPG comparison before/after mods
- Bronco6G, To upgrade or not to upgrade
- Bronco6G, 5.13 or 5.38 gears on 37's
- Bronco6G, Gearing with 35s
- Overland Bound, Jeep Gladiator mileage question
- Expedition Portal, '23 JL regear with 35s?
- Tacoma World, Effect of tires and gears on MPG
- Tacoma4G, 33s and drivability
- Tacoma World, 4.10 gears and 33's
- Tacoma World, Mpg questions
- Tacoma3G, 5.29 fuel mileage thread
- Tacoma World, Those running 33's, what's your mpg?
- Tacoma3G, 4.88 gears
- 4Runners.com, 285/70/17 tires and fuel mileage
- 4Runner6G, 2026 4Runner non-hybrid MPG
- Trail4Runner, 4.56 regear on a 5th gen 4Runner
- Trail4Runner, Why did you re-gear?
- Trail4Runner, 4.88 gears on a 5th gen