Miata Tire Guide: NA, NB, NC, ND Sizes & Factory Setups
Factory tire sizes, pressures and lug nut torque for the NB, NC and ND MX-5 from Mazda's owner's manuals, with calculated diameters for each size.
Quick answer
Mazda's owner's manuals list 195/50R15 and 205/45R16 for the NB, 205/50R16 and 205/45R17 for the NC, and 195/50R16 and 205/45R17 for the ND. The manuals warn that fitting a size other than the one specified could seriously affect ride, handling, ground clearance and speedometer calibration, so check any other size with a Mazda dealer. Diameters on this page are calculated from the size.
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Compare exact Miata tire sizes before changing wheels
Use the calculator for exact diameter, sidewall and speedometer math against the Mazda factory size.
Miata generations overview
Sizes, pressures and lug nut torque below come from Mazda U.S. owner's manuals. Where we could not find or read a manual, the row says so instead of guessing.
NA Miata
1989–1997Factory sizes
Not covered — no official Mazda owner's manual found
Pressure and torque
Cold pressure: Check the tire label or ask a Mazda dealer
Lug nut torque: Check with a Mazda dealer
Note
Look at the tire label on the car, then type that size into the Miata Tire Size Calculator.
NB Miata
2002–2005Factory sizes
195/50R15 82V, 205/45R16 83W (2005 manual also lists 205/40R17 80W)
Pressure and torque
Cold pressure: 180 kPa (26 psi); 17 inch size in the 2005 manual 200 kPa front / 220 kPa rear
Lug nut torque: 88–118 N·m (65–87 ft·lbf)
Note
The 1999 to 2001 manuals are scans we could not read, so those model years are not covered.
NC Miata
2006–2014Factory sizes
205/50R16 87V, 205/45R17 84W
Pressure and torque
Cold pressure: 200 kPa (29 psi) front and rear
Lug nut torque: 88–118 N·m (65–87 ft·lbf)
Note
The same two sizes appear in the 2006, 2008, 2010 and 2014 manuals.
ND Miata
2016–2026Factory sizes
195/50R16 84V, 205/45R17 84W
Pressure and torque
Cold pressure: 200 kPa (29 psi) front and rear
Lug nut torque: 108–147 N·m (80–108 ft·lbf)
Note
The ND manual also warns about tire clearance when a non-specified size is fitted.
OEM tire sizes by generation
Sizes and ratings are from Mazda's owner's manuals. Diameter, sidewall-based figures and revolutions per mile are calculated from the size.
| Model / years | Tire (manual) | Rim | Diameter in (calc.) | Diameter mm (calc.) | Revs/mile (calc.) |
|---|---|---|---|---|---|
| NB (2002–2005) | 195/50R15 82V | 15 inch | 22.68 | 576.0 | 889 |
| NB (2002–2005) | 205/45R16 83W | 16 inch | 23.26 | 590.9 | 867 |
| NB (2005) | 205/40R17 80W | 17 inch | 23.46 | 595.8 | 860 |
| NC (2006–2014) | 205/50R16 87V | 16 inch | 24.07 | 611.4 | 838 |
| NC (2006–2014) | 205/45R17 84W | 17 inch | 24.26 | 616.3 | 831 |
| ND (2016–2026) | 195/50R16 84V | 16 inch | 23.68 | 601.4 | 852 |
| ND (2016–2026) | 205/45R17 84W | 17 inch | 24.26 | 616.3 | 831 |
15 vs 16 vs 17 inch wheels
The wheel diameter alone does not set the tire's overall diameter. The table below compares sizes that Mazda lists for the same generation; every figure is calculated. The plus sizing options for a larger wheel and the low profile tire guide cover the choice of wheel diameter.
| Generation | Size A | Size B | Diameter change (calc.) | Change % |
|---|---|---|---|---|
| NB | 195/50R15 | 205/45R16 | +0.59″ | +2.59% |
| NB | 205/45R16 | 205/40R17 | +0.19″ | +0.83% |
| NC | 205/50R16 | 205/45R17 | +0.19″ | +0.80% |
| ND | 195/50R16 | 205/45R17 | +0.59″ | +2.48% |
Across generations the factory diameters run from 22.68 inches (NB 195/50R15) to 24.26 inches (NC and ND 205/45R17), so a size that is correct for one generation is not automatically close to another's.
Checking a different size
Mazda's manuals warn that using a tire size other than the one specified could seriously affect ride, handling, ground clearance and speedometer calibration. The ND manual adds tire clearance to that list. A side-by-side diameter comparison and the wheel clearance estimate are the next checks.
- Compare the new size with the Mazda factory size in the calculator to see the diameter change and speedometer error.
- Continental advises keeping rolling circumference within 3% of the original; this is not a Mazda specification.
- The manuals do not publish bolt pattern, centre bore, offset or fender clearance, so confirm those with a Mazda dealer or the wheel maker.
- Use the lug nut torque in the table above when installing wheels: 88–118 N·m on NB and NC, 108–147 N·m on ND.
What this guide does not cover
Mazda's owner's manuals do not give wheel width, offset, bolt pattern or track and autocross tire advice, so none of those are listed here. NA (1989–1997) and 1999–2001 factory sizes are also missing because we have no readable official manual for them.
Try the Miata Tire Size Calculator
Decode any tire size, compare it with the factory diameter and check the speedometer error.