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2020 Mazda MX-5 Miata Tire Fitment

2 factory tire sizes across trims — select yours below.

Trim fitment

Trim(s) OEM size
Sport 195/50R16 Specs →
Club, Grand Touring 205/45R17 Specs →
OEM size
205/45R17
Diameter
24.26″
Sidewall
3.63″
Revs / mile
831

About 2020 Mazda MX-5 Miata fitment

The 2020 Mazda MX-5 Miata Club ships from the factory with 205/45R17 tires, giving a 24.26″ overall diameter and 831 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 24.26″ to preserve correct readings. This model year ships in multiple configurations with different OEM tire sizes (205/45R17, 195/50R16), so confirm your exact trim badge before ordering. The smallest recommended upsize is 215/40R18 — a 2.09% diameter change — which keeps the speedometer inside factory tolerance while adding marginal ride height and sidewall compliance. The most aggressive option shown, 235/40R18, runs 4.69% taller and will likely need clearance checking on stock suspension. For a direct replacement, look for brands offering 205/45R17 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

Size Diameter Δ vs OEM
215/40R18 24.77″ +2.09% Details →
215/45R17 24.62″ +1.46% Details →
225/45R17 24.97″ +2.92% Details →
205/50R17 25.07″ +3.33% Details →
225/40R18 25.09″ +3.39% Details →
235/45R17 25.33″ +4.38% Details →
235/40R18 25.4″ +4.69% Details →

Check speedometer error before upsizing

Type to search · try 275/65R18 or "33" for inch aliases
Common upsizes from 205/45R17:
Don't know your stock size? Load it by vehicle:

205/45R17

Diameter
24.26″ / 616.3mm
Section Width
8.07
Sidewall
3.63″ / 92.25mm
Circumference
76.23
Revs/Mile
831
See tires in 205/45R17

215/40R18

Diameter
24.77″ / 629.2mm
Section Width
8.46
Sidewall
3.39″ / 86mm
Circumference
77.82
Revs/Mile
814
See tires in 215/40R18
205/45R17 · 24.26215/40R18 · 24.77

Speedometer & Diameter Impact

Different rim — new wheels required
Diameter Change
+2.09%
Sidewall Change
-0.24″
Revs/Mile Δ
-17
mph

At an indicated 60 mph, your actual speed is 61.26 mph (98.58 km/h). Your speedometer reads 2.09% low versus actual speed.

Speedometer impact if you upsize from 205/45R17

Mazda MX-5 Miata — other model years