2021 Acura MDX Tire Fitment
3 factory tire sizes across trims — select yours below.
Trim fitment
About 2021 Acura MDX fitment
The 2021 Acura MDX A-Spec ships from the factory with 265/45R21 tires, giving a 30.39″ overall diameter and 664 revs per mile. This is the reference size the factory speedometer, odometer, ABS, and TPMS were calibrated against, so any replacement tire should stay close to 30.39″ to preserve correct readings. This model year ships in multiple configurations with different OEM tire sizes (265/45R21, 255/60R18, 275/45R21), so confirm your exact trim badge before ordering. The smallest recommended upsize is 285/40R22 — a 1.93% diameter change — which keeps the speedometer inside factory tolerance while adding marginal ride height and sidewall compliance. The most aggressive option shown, 295/45R21, runs 3.50% taller and will likely need clearance checking on stock suspension. For a direct replacement, look for brands offering 265/45R21 in all-season, highway, or terrain-appropriate compounds — the OEM spec typically emphasizes fuel economy and tread life over grip, so aftermarket replacements often unlock better wet performance or off-road capability at similar cost. Before committing to an upsize, confirm wheel-well clearance at full steering lock and suspension compression, and verify the chosen size does not conflict with snow chains, tire-fit sensors, or any lift-kit hardware already installed.
Upsize options
Check speedometer error before upsizing
275/65R18 or "33" for inch aliases265/45R21
- Diameter
- 30.39″ / 771.9mm
- Section Width
- 10.43″
- Sidewall
- 4.69″ / 119.25mm
- Circumference
- 95.47″
- Revs/Mile
- 664
285/40R22
- Diameter
- 30.98″ / 786.8mm
- Section Width
- 11.22″
- Sidewall
- 4.49″ / 114mm
- Circumference
- 97.32″
- Revs/Mile
- 651
Speedometer & Diameter Impact
Different rim — new wheels requiredAt an indicated 60 mph, your actual speed is 61.16 mph (98.42 km/h). Your speedometer reads 1.93% low versus actual speed.