RAM Truck Tire Size Guide
Tire sizes from RAM owner's manuals for the 1500, 1500 Classic, 2500 and 3500, with calculated diameters, lug nut torque and speedometer examples.
RAM 1500
The 2025 manual lists 275/65R18 and 275/55R20 for Tradesman, HFE, Big Horn / Lone Star and Laramie, and 275/55R20 for Longhorn, Sport and Limited. Calculated diameters are 32.07 and 31.91 inches.
RAM 2500
The 2025 manual lists LT245/70R17E, LT285/70R17D, LT275/70R18E and LT285/60R20E by trim. Calculated diameters run from 30.50 to 33.46 inches.
What the manuals do not say
RAM's owner's manuals do not publish lift limits, leveling-kit sizes, bolt patterns or maximum tire sizes, so this guide does not either.
Before you buy RAM tires
Compare stock vs another size with the calculator
Pick your trim and enter a target size to see the diameter change and speedometer error.
RAM 1500 DT (5th gen, 2019–present) stock sizes by trim
Sizes are from RAM's 2020 and 2025 owner's manuals (snow traction device tables). Height and revolutions per mile are calculated.
| Trim | Manual | Tire (manual) | Height in (calc.) | Revs/mile (calc.) |
|---|---|---|---|---|
| Tradesman, HFE, Big Horn / Lone Star, Laramie | 2025 | 275/65R18 | 32.07 | 629 |
| Tradesman, HFE, Big Horn / Lone Star, Laramie | 2025 | 275/55R20 | 31.91 | 632 |
| Longhorn, Sport, Limited | 2025 | 275/55R20 | 31.91 | 632 |
| All 1500 models (2020 manual) | 2020 | 275/65R18 and 275/55R20 | 32.07 / 31.91 | 629 / 632 |
| Rebel | 2025 | Listed as not chainable; no size given | — | — |
RAM 1500 Classic (DS, 2009–2021) stock sizes
The 2020 Classic manual lists one size and gives no trim breakdown.
| Entry | Tire (manual) | Height in (calc.) | Revs/mile (calc.) |
|---|---|---|---|
| Tire chain size listed (2020 manual) | P265/70R17 | 31.61 | 638 |
RAM 2500 stock tire sizes by trim
From the 2025 manual. Heights are calculated.
| Trim | Tires (manual) | Heights in (calc.) |
|---|---|---|
| 4x2 Tradesman | LT245/70R17E, LT275/70R18E | 30.50, 33.16 |
| 4x2 Big Horn, Laramie, Limited | LT275/70R18E, LT285/60R20E | 33.16, 33.46 |
| 4x4 Tradesman | LT245/70R17E, LT285/70R17D, LT275/70R18E | 30.50, 32.71, 33.16 |
| 4x4 Big Horn, Laramie, Limited | LT275/70R18E, LT285/60R20E | 33.16, 33.46 |
| 4x4 Power Wagon | LT285/70R17D, LT275/70R18E, LT285/60R20E | 32.71, 33.16, 33.46 |
RAM 3500 stock tire sizes (SRW and DRW)
From the 2025 manual. Heights are calculated.
| Configuration | Tires (manual) | Heights in (calc.) |
|---|---|---|
| SRW 4x2 and 4x4 Tradesman | LT275/70R18E | 33.16 |
| SRW 4x2 and 4x4 Big Horn, Limited, Laramie, Longhorn | LT275/70R18E, LT285/60R20E | 33.16, 33.46 |
| DRW 4x2 and 4x4 (all listed trims) | LT235/80R17E | 31.80 |
Lug nut torque
| Model | Torque (manual) | Nut |
|---|---|---|
| RAM 1500 (2020, 2025) | 130 ft-lb (176 N·m) | Cone nut, M14 x 1.5, 22 mm socket |
| RAM 1500 Classic (2020) | 130 ft-lb (176 N·m) | Cone nut, M14 x 1.5, 22 mm socket |
| RAM 2500 / 3500 (2025) | 130 ft-lb (176 N·m) cone; 129 ft-lb (175 N·m) flanged | M14 x 1.5, 22 mm socket |
RAM speedometer correction reference
True speed = indicated speed × (new diameter ÷ stock diameter). Each row compares two sizes RAM lists for the same truck; all figures are calculated. The speedometer error calculator does the same sum for any two sizes, and the effective gear ratio after a tire change is calculated separately.
| From | To | Change | True speed at 60 mph indicated |
|---|---|---|---|
| 275/65R18 | 275/55R20 | -0.17″ (-0.5%) | 59.7 mph |
| LT245/70R17E | LT285/70R17D | +2.20″ (+7.2%) | 64.3 mph |
| LT285/70R17D | LT275/70R18E | +0.45″ (+1.4%) | 60.8 mph |
| LT275/70R18E | LT285/60R20E | +0.31″ (+0.9%) | 60.6 mph |
Checking a different size
- RAM's manuals warn that using tires of different size or type between the front and rear axles can cause unpredictable handling.
- The manuals do not publish maximum tire size, lift or leveling-kit requirements, bolt pattern or offset, so confirm those with a RAM dealer or the wheel maker.
- Continental advises keeping rolling circumference within 3% of the original; this is not a RAM specification.
- Load range letters on RAM 2500 and 3500 tires are explained in the ply rating and load range guide, and the truck tire guide compares the major pickups.
Before ordering RAM tires
Verify diameter change and speedometer impact
Pick your RAM trim, enter your target size, and see the diameter difference and speedometer error.
Sizes listed are the ones in RAM owner's manuals (2020 to 2025). The Rebel, TRX and RHO have no size listed in the manuals we read, and RAM may change wheel packages by year, so check your tire placard.