Date Published: February 27, 2026 | Last Modified: 1 hour ago | 3 minute read | Verified by Mitchell Bazinet at Redwater Dodge

37-Inch Tires on Ram 2500s

Understanding Tire Sizes for RAM 2500s

The "Lease Road" Reality: Why Tire Choice Beats Size

Most drivers jump straight to the size of the tire, but on gravel and lease roads, tire construction is king. A 37-inch highway tire will fail you faster than a 33-inch heavy-duty hybrid. When you are running back and forth on gravel, you need a tire with:

Stone Ejection: High-quality treads designed to "spit out" rocks rather than holding onto them. This prevents "stone drilling," where a rock eventually punctures the casing.

Sidewall Strength: Thicker sidewalls protect against sharp shale and jagged ruts common on remote work sites.

Hybrid Tread Patterns: For the best of both worlds, look at the hybrid All-Terrain/Mud-Terrain category. These offer the grip needed for slick mud without the deafening road noise or poor wear of a pure MT.

Do You Need to Re-Gear for 37s? 

This is the most common technical question we receive. The answer depends entirely on your powertrain:

The Diesel Advantage: If you are running a Cummins Turbo Diesel with 3.73 gears, the massive low-end torque makes 37s "livable." You will notice a slight change, but the engine can handle the load.

The Gas Truck Challenge: For HEMI-powered 2500s, taller tires can lead to "gear hunting" (the transmission constantly shifting to find the right power band). You’ll likely see higher RPMs on the highway and increased transmission temperatures when the truck is working hard. In these cases, moving to 4.10 gears is highly recommended to restore your truck's mechanical advantage.

The Hidden Cost: Braking and Rotating Mass

Nobody talks about stopping until they can’t. By moving to 37s, you aren't just adding height; you are adding significant rotating weight. This creates more kinetic energy that your brakes have to dissipate.

Stopping Distance: Expect it to increase.

Towing: If you frequently haul heavy trailers, the added tire weight makes your brake controller settings and brake pad quality more critical than ever. We recommend high-performance pads to compensate for the larger footprint.

The "Alberta Question": Is it Legal?

In Alberta, 37s are perfectly legal for highway use, provided your setup remains compliant with safety standards. This means:

Tire Coverage: Fenders or flares must properly cover the tread to prevent throwing debris at other motorists.

Lift Limits: Your lift kit must stay within legal height requirements.

Safety Equipment: Ensure your mud flaps are still effective and your headlights are re-aimed downward to account for the new height—otherwise, you'll be blinding oncoming traffic.

The Trade-Off: Fuel vs. Performance

Let's be honest: you don't buy 37s to save money at the pump. Larger tires increase wind resistance and change your effective gear ratio, which will hurt your fuel economy. However, the trade-off is found in ride quality. On rough lease roads, that extra sidewall acts as an additional layer of suspension, soaking up "washboard" ripples and providing a larger footprint for better stability in the dirt.

Additional Questions & Answers

Q1. Will 37-inch tires void my Ram 2500 factory warranty?

A1. Generally, the tire size itself won't void your entire warranty, but it can affect claims related to the drivetrain, suspension, or wheel bearings if the larger tires are found to be the cause of the failure. We recommend Mopar-certified lift kits to maintain the best coverage.

Q2. Do I need a lift kit to fit 37s, or will a leveling kit work?

A2. On newer Ram 2500s, a high-quality 2.5" to 3" leveling kit can fit 37s, but you may experience rubbing on the radius arms or fender liners at full lock. A 4" lift is the "sweet spot" for 37s to ensure zero interference during off-road articulation.

Q3. How do 37s affect my speedometer and odometer?

A3. Your speedometer will read slower than your actual speed (usually by 5–10%). Mitch at Redwater Dodge can book an appointment with service to recalibrate your truck’s computer so your safety systems, shift points, and odometer remain accurate.

Q4. Which brands do you recommend for lease road use?

A4. We see the best results with the Toyo Open Country R/T or M/T, and the BFGoodrich KO2 or KM3. These brands offer the puncture resistance necessary for oil field work.