The usual shorthand is that the Superturismo is cast and the Ultraleggera is flow-formed. Read OZ’s own product pages and that turns out to be wrong.
Both standard-line wheels are made the same way — low-pressure cast monoblock, heat treated, made in Italy. The Ultraleggera is lighter because of its spoke design, not because of a different process.
The Short Version
- Superturismo GT and standard Ultraleggera use the same manufacturing process. Low-pressure cast monoblock, heat treated.
- Flow-forming is a separate line. OZ calls it HLT, and it is reserved for the I-Tech products — Ultraleggera HLT, Superturismo AERO.
- The weight gap is real: roughly 25.0 lb versus 18.4 lb at 18×8, about six pounds a corner.
- “Ultraleggera” on a used listing is ambiguous. HLT and non-HLT are different wheels at different weights and prices, and sellers rarely say which.
- Both current lines are made in Italy, per OZ’s own pages.
What Each One Is
| Model | Construction | Sizes | Offset | Width | Weight, 18×8 |
|---|---|---|---|---|---|
| Superturismo GT | Low-pressure cast monoblock, heat treated | 14–19″ | +15 to +50 | 6–8J | ~24.85–25.0 lb |
| Superturismo LM | Same, plus HLT on the 21″ | 17–21″ | +20 to +50 | 7–10.5J | not sourced |
| Ultraleggera | Low-pressure cast monoblock, heat treated | 15–18″ | +16 to +55 | 7–9J | ~18.4–18.8 lb |
| Ultraleggera HLT | Flow-formed | wider range, larger sizes | — | — | lighter still, not sourced |
The 14-inch bottom end of the Superturismo GT range is worth noticing. That is a rally-derived size, and it is why this wheel turns up on classic Fiats, Peugeots and Escorts as often as on modern cars.
Where the Six Pounds Comes From
The Ultraleggera runs six thin double spokes. The Superturismo GT runs a much heavier multi-spoke face derived from a rally wheel that had to survive gravel.
Same alloy, same casting process, same heat treatment — different amount of metal. That is the entire explanation, and it is a more honest one than “one is flow-formed.”
It also tells you something about intent. OZ positions the Superturismo GT as its motorsport icon, and its own copy claims roughly 90% of the WRC field ran it in Race White at one point. The Ultraleggera is positioned as the lightweight benchmark for road cars — the name means “ultra light” and it is doing what it says.
The Buying Trap: HLT or Not
This is the practical warning, and it applies specifically to used purchases.
OZ sells an Ultraleggera and an Ultraleggera HLT. They share a name and a look. One is cast; the other is flow-formed and lighter. They were sold at different prices.
Sellers routinely list both as simply “OZ Ultraleggera.” If weight is the reason you want the wheel, ask which one it is and get it in writing — and be aware that the answer changes what the set is worth.
Checking a Used Set
Both are cast, so inspect them as cast wheels. That means looking for porosity, weld repairs, and corrosion at the bead seat, rather than for the joint problems you would check on a three-piece.
Check the offset against your car, not against the range. OZ’s fitment ranges are wide — the Superturismo GT spans +15 to +50 — because the wheel is offered for many chassis. Being inside the range means nothing on its own.
Check the size before you fall in love with a photograph. The Ultraleggera stops at 18 inches in its standard form. If you have seen a 19 or 20 inch Ultraleggera, you are looking at HLT.
What We Could Not Verify
- Launch year of the original Superturismo nameplate. Secondary sources put the aftermarket adaptation around 2004; the racing wheel behind it is older, and OZ does not publish a date we could find.
- Launch year of the Ultraleggera. 2005 circulates in aggregator guides; it is not on ozracing.com.
- Per-size weights for the Superturismo LM and the Ultraleggera HLT. Only the GT and standard Ultraleggera at 18×8 were independently sourced.
- Whether every OZ line is Italian-made. We confirmed it for these specific models; the OZ Group produces elsewhere too and we did not map that.
Related Guides
- OZ Racing brand profile — the rally origins, and the Japanese-made models
- BBS LM vs RG — the same question asked of forged wheels
- Porsche 911 and BMW M3 E46 — two cars these turn up on constantly
Finding a Set
OZ has a long history in Japan and used sets circulate here in sizes that are hard to find elsewhere — particularly the smaller Superturismo fitments. Tell us the car and, importantly, whether you want HLT or standard. The Request page is the place.