Ram · Factory fitment
Ram 2500 tire size by year
Every factory tire size the 2500 was sold on from 2003–2026, worked out in inches, with the wheels they were fitted to.
2003–2026 · 3rd–5th gen
275/70R18
33.2" overall · 10.8" section width
Factory wheels: 18x8, 20x8
Trim and wheel package decide which of these your truck actually has. The placard inside the driver's door jamb is the authority for your specific vehicle, and it also carries the cold inflation pressures that go with each size.
2500 factory tire sizes, generation by generation
Every 2500 tire size in inches
Metric sizes are hard to compare by eye. Here they are converted — overall diameter is what decides clearance, speedometer accuracy and effective gearing.
2500 tire sizes — frequently asked
What size tires does a Ram 2500 take?
The 2003–2026 Ram 2500 was sold from the factory on 275/70R18, 285/60R20, on 18x8, 20x8 wheels. Which one your truck has depends on its trim and wheel package, so check the placard inside the driver's door jamb — that sticker lists the sizes your specific truck left the factory on, together with the correct cold inflation pressures.
How tall is a 275/70R18 tire in inches?
About 33.2 inches overall. The sidewall is 7.6 inches tall (70 per cent figures are of the section width, not the wheel), the section width is 10.8 inches, and it turns roughly 608 revolutions per mile. Those are the numbers to compare against when you are sizing up.
What is the biggest factory tire on a 2500?
Across 2003–2026 the largest factory size on record is 285/60R20 at about 33.5 inches tall, and the smallest is 275/70R18 at about 33.2 inches. If your truck came on the smaller size, the larger one is a known-good fitment for the same platform — which makes it the safest first upsize, though offset and trim still differ.
Can I put bigger tires on my 2500 without a lift?
Usually one size, around 3 per cent more overall diameter, fits on stock suspension. Past that you are into trimming the front valance or fitting a levelling kit, and the limiting factor is often the wheel offset rather than the tire height — a wider tire on a lower offset hits the fender liner at full lock long before diameter becomes the issue. Work out the exact clearance before you buy.
Do bigger tires affect the 2500's speedometer?
Yes, proportionally. A tire 3 per cent taller than stock makes the speedometer read about 3 per cent low, so an indicated 70 is really 72, and the odometer under-counts by the same amount. It also shifts the effective gear ratio, which on a truck that tows is felt as softer acceleration and more downshifting on grades.
What wheels fit a 2500?
Wheel fitment starts with the bolt pattern, then hub bore, then offset. All three for every 2500 generation are on the bolt pattern page for this truck, along with the stud thread and lug torque. The factory wheel sizes on this page tell you what widths and diameters the truck was engineered around.
