Mud Tires for a Ram 2500

Start with what Ram fits

Ram’s 2026 Heavy Duty buyers guide lists five tires for the single-rear-wheel 2500. Four are Load Range E: a Firestone Transforce HT in LT245/70R17 on the base truck and in LT275/70R18 on most trims, a Firestone Transforce On-/Off-Road in LT275/70R18 with the Off-Road Package, and an LT285/60R20 all-terrain. The Power Wagon is the exception: a Goodyear Wrangler DuraTrac in LT285/70R17, Load Range D.

Tires from Stellantis Fleet’s 2026 Ram Heavy Duty buyers guide. Heights are calculated from the size, not measured.

The load range question, in numbers

Ram lists a maximum GVWR of 11,040 lb for the 2026 2500. Individual configurations sit lower: Ram’s spec pages show 10,000 lb for a two-wheel-drive Limited with the 6.4-litre HEMI and 8,565 lb for the Power Wagon.

The factory Transforce HT in LT275/70R18 is a 125/122S tire rated 3,640 lb at 80 psi on tiresize’s figures: 14,560 lb across four, 1.32 times that 11,040 lb maximum. That is a much thinner margin than on a half-ton, and the weight is not spread evenly: a diesel carries far more over the front axle. The number that matters is on the door-jamb sticker. Each axle’s GAWR must be no more than twice the rating of one tire on it.

This is where bigger can be weaker. A mud-terrain in the factory LT275/70R18 size is rated 3,640 lb in Load Range E, exactly what it replaces. A 35×12.50R20 in Load Range E is rated only 3,195 lb, 445 lb less per tire than the factory 18. The F-rated versions carry 3,640 lb, level with stock. On a truck Ram rates to tow 20,000 lb with the diesel and 17,750 lb with the gas engine, that difference is not academic.

The weight penalty

The factory Transforce HT weighs 49 to 50 lb in LT275/70R18. A Load Range E mud-terrain in the same size weighs 62.3 lb (BFGoodrich KM3) to 66.1 lb (Falken Wildpeak M/T): 12 to 17 lb more per corner. A 35×12.50R20 weighs 72.5 to 79.0 lb, 22 to 30 lb more per corner. Our fuel economy guide covers how that shows up at the pump.

What fits without a lift

Ram publishes no maximum tire size, so we will not invent one. What the numbers do show: in LT275/70R18, the six mud-terrains we track measure 33.2 to 33.6 inches, level with the factory tire, so on an 18-inch truck a mud-terrain in the factory size changes almost nothing but the tread. On 20s, LT275/65R20 measures 34.1 to 34.5 inches, 0.6 to 1 inch over the factory LT285/60R20.

On a Power Wagon, LT285/70R17 is the factory size, and the six mud-terrains measure 32.8 to 33.15 inches in it. In Load Range E they run a heavier casing than the factory DuraTrac’s D.

What a lift actually buys

ReadyLIFT publishes a tire size for each Ram 2500 kit, which makes its claims checkable. All three below are for 2019-on diesel trucks, and none is for the Power Wagon.

Its 1.5-inch coil-spring leveling kit (46-19122) states a 35×12.50 on a 20×9 wheel at 0 offset. It is not for trucks with factory air suspension, which ReadyLIFT says are leveled from the factory, so the kit would over-lift the front. Its 3-inch SST2.1 kit (63-19340) states a 35×12.50 with no rubbing on the same 20×9, 0 offset wheel; it is for standard-output diesels only, and not for air suspension or auto-level trucks. Its 4.5-inch front, 2.5-inch rear SST kit (69-19450) states a 37-inch diameter tire on a wheel of up to −18 mm offset, with the same exclusions. Check the kit page for your exact truck before you buy anything.

Gearing and the speedometer

Ram’s buyers guide lists 3.73 as the standard axle ratio on the 2500, with 3.42 and 4.10 offered with certain packages. Going from the factory 33.2-inch LT275/70R18 to a 35×12.50R20 measuring 34.5 to 35.0 inches is 4 to 5.5% taller. From the base truck’s 30.5-inch LT245/70R17 to LT285/70R17 at 32.8 to 33.15 inches is 7.5 to 8.7%. The speedometer reads low by the same share. Our tire size calculator does this arithmetic for any size pair.

What is actually made in Ram 2500 sizes

Of the six mud-terrains we track (BFGoodrich KM3, Nitto Trail Grappler, Toyo Open Country M/T, Falken Wildpeak M/T, Maxxis RAZR MT and Milestar Patagonia M/T-02), these are the sizes that suit a Ram 2500:

Tire Size (tiresize.com) model specification pages, as collected in our specification dataset. Load is the single-tire rating for the Load Range E version unless marked.

Read the last column before the second one. On a three-quarter-ton, the tallest tires here are not the strongest: LT295/70R18 and LT275/65R20 out-carry both 35-inch sizes in Load Range E.

What we would buy

On an 18-inch truck: LT275/70R18, the factory size, in whichever of the six is cheapest that week (the price tracker has dated prices). Same height, same 3,640 lb rating, nothing new to rub.

Wanting more tire on 18s: LT295/70R18, at about 34.5 inches the highest-rated size here at 4,080 lb, from the four makers that offer it. It is under the 35-inch diameter ReadyLIFT states for its diesel kits, but ReadyLIFT states its wheel fitment on 20s, so confirm it for 18-inch wheels first.

On a leveled or lifted diesel with 20s: a 35×12.50R20 in Load Range F if you tow or haul near the truck’s ratings, because the E version carries less than the tire it replaces. On a Power Wagon: LT285/70R17 in Load Range E, the factory size in a heavier casing.