The Short Version
- 4×114.3, confirmed on RS Watanabe’s own matching list for the S30 and S31.
- Front and rear take different wheels. Watanabe’s standard fitment is A14-70 (+3) at the front and B14-75 (+1.5) at the rear — different width, different offset.
- The 240ZG is a separate fitment, running negative offsets that the standard car does not.
- Hub bore is not published by any manufacturer source. The best figures we found are hobbyist caliper measurements, and they are different front and rear.
The Fitment Table
| Model | PCD | Standard fitment | Maximum fitment | Note |
|---|---|---|---|---|
| Fairlady Z S30 / S31 | 114.3-4 | F: A14-70 (+3) / R: B14-75 (+1.5) | F: F8 15-70 (+1) / R: F8 15-75 (+2); alternatively F: F8 15-75 (+8.5) / R: F8 15-80 (+7) | — |
| 240ZG (JDM G-nose) | 114.3-4 | F: R15-85 (−6) / R: R15-95 (−19) | F: R16-85 (−6) / R: R16-90 (−13) | F: 225/50, R: 245/45 |
The thing to take from this is that the S30 is a staggered car from the start — not dramatically, but the front and rear are specified differently even in the standard fitment. A set of four identical wheels is a choice, not the default.
The 240ZG is the wide-arched, long-nosed JDM homologation car, and its numbers are in another world: −6 at the front and −19 at the rear on 15-inch R-types, carrying 225 and 245 section tyres. Those wheels will bolt to a standard S30 and will stick a long way out of it.
The Hub Bore Question, Answered as Honestly as We Can
RS Watanabe publishes no hub-bore figure for the S30. That absence is more informative than it looks, because two rows above the S30 on the same document, they explicitly flag the SR311 Fairlady roadster with ハブ径要確認！ — hub bore, please confirm — and add a reference note that one example needed a φ77 hub hole machined down five millimetres. They also publish bores for the Sunny, the 510 Bluebird, the CSP311 Silvia and the Y30 Cedric.
So RS Watanabe flags hub bore when it matters operationally, and they did not flag it for the S30. As with the Hakosuka, our reading — and it is our reading, not their statement — is that these tapered-seat wheels locate on the nut rather than the hub, which is why the bore is a clearance question rather than a fitment question.
For what it is worth, the most concrete numbers we found come from a 2007 forum post where an owner measured with calipers: three 240Z front hubs at 72.7 to 72.9 mm, and three rear stub axles at 67.9 to 68.1 mm. The widely repeated “73 mm” figure is that front measurement rounded up.
Note what that implies: the S30 has independent rear suspension, so the front hub and the rear stub axle are different diameters. There is no single “S30 hub bore”. Anyone quoting you one number for both ends has not measured the car.
We are publishing those figures as what they are — careful hobbyist measurements, not a factory specification. Do not order hub rings against them without measuring your own car.
Factory Wheels
The commonly cited factory sizes are 14×4.5J at +15 for Series 1 cars (1970–71) and 14×5J at +15 from Series 2 onward, both 4×114.3. We have this from a US specialist retailer’s own guide rather than from a Japanese factory table, so treat it as good trade knowledge rather than as verified specification.
What is worth noticing is the gap between those numbers and what people actually run. The factory +15 on a 4.5J is a long way inboard of Watanabe’s +3 on a 7J. The period look everybody wants is not the factory look.
JDM Versus Export
The car was sold in Japan as the Fairlady Z and abroad as the 240Z, with the 260Z and 280Z following in export markets. The JDM-only cars that matter are the Z432, which carries the same S20 twin-cam engine as the Hakosuka GT-R, and the 240ZG.
Of those, only the 240ZG has a distinct fitment in RS Watanabe’s data. We found no source establishing any wheel or hub difference between a JDM Fairlady Z and an export 240Z, so we are treating them as the same fitment while flagging that we did not confirm it.
Importing
The S30 ran from 1969 to 1978. Everything is decades past the 25-year mark, and the 240Z was sold new in the United States in large numbers, so the shape is familiar and the parts network is excellent.
The cars worth importing from Japan are the ones the US never got: the Z432, the 240ZG, and right-hand-drive Fairlady Zs generally.
What We Could Not Verify
- A factory hub bore figure for the S30, front or rear. What we have is a hobbyist measurement, cited as such.
- Any wheel or hub fitment difference between the JDM Fairlady Z and the export 240Z, other than the 240ZG which Watanabe documents separately.
- Stud thread and pitch. RS Watanabe gives no thread note on the S30 row.
- Factory wheel sizes from a Japanese primary source; our figures are from a US specialist’s guide.