The Short Version
- MAT is not forging, and Enkei does not claim it is. It is casting plus rim spinning, and Enkei explains honestly why that matters.
- Enkei does not market the RPF1 with a JWL or VIA claim. It markets its own standard instead.
- Still in production, with a wide-lip companion called RPF1RS. There is no RPF2.
- No load rating is published per size, and several sizes have no published weight either.
What MAT Actually Is
MAT stands for Most Advanced Technology, which tells you nothing. Here is what Enkei’s own engineering page says it does.
Two processes are combined. The first is Durville die casting: molten alloy is poured in from the inner rim side with the disc face down, so the wheel solidifies directionally and quickly, giving a finer grain structure at the face where the load goes. The second is spinning — the cast rim is rolled on a mandrel after casting, which stretches and aligns the metal in the rim in a way Enkei describes as similar to forged grain structure.
Enkei’s claim for the result on the RPF1 specifically: the MAT process reduces wheel weight by 10 to 15 per cent against an equivalent conventional cast wheel.
The Honest Bit About Forging
What makes Enkei’s engineering page unusually good reading is that it does not oversell. It states plainly that cast and forged aluminium alloys have the same Young’s modulus and the same specific gravity.
In plain terms: forging does not make aluminium stiffer, and it does not make it lighter. What forging genuinely improves is yield and tensile strength — how much stress the material takes before it deforms permanently.
That is more useful to understand than any marketing claim, because it tells you what you are buying when you pay four times as much for a forged wheel. You are buying strength margin, which lets the designer use less material for the same safety factor. You are not buying a fundamentally different metal.
Enkei’s position is that MAT captures a useful part of that benefit at a cost much closer to casting, with more freedom in the face design than forging allows. That is a reasonable claim, and it is why the RPF1 sits where it does in the market.
The Range Is the Real Story
The RPF1’s reputation is built on being light and cheap. What actually sustains it is that Enkei makes it in an unusually wide spread of fitments.
| Parameter | Range offered |
|---|---|
| Diameter | 14, 15, 16, 17, 18 inch |
| Bolt patterns | 4×100, 4×114.3, 5×100, 5×112, 5×114.3, 5×120 |
| Offsets | as low as +15, up to +48 |
| Centre bores | 54 to 75 mm depending on fitment |
Six bolt patterns across a 14-to-18-inch spread is not normal for a single model. It is why the same wheel turns up on a 4×100 Civic, a 5×114.3 Silvia and a 5×120 BMW, and why the recommendation is so universal.
Published Weights
Enkei publishes these per part number. A sample:
- 14×7 ET28, 4×100 — 8.40 lb (about 3.8 kg)
- 15×8 ET28, 4×100 — 11.35 lb (about 5.1 kg)
- 16×7 ET43, 4×100 — 13.70 lb (about 6.2 kg)
- 17×9 ET45, 5×114.3 — 15.65 lb (about 7.1 kg)
- 18×10.5 ET15, 5×114.3 — 19.05 lb (about 8.6 kg)
Worth noting: a number of part numbers in Enkei’s own table show weight as N.A. If you are buying for weight specifically, check whether your exact fitment has a published figure rather than assuming the one you read for a different size applies.
Spec-E, Not JWL
This surprised us, and it needs stating carefully.
We looked for a JWL or VIA marking claim on Enkei’s own RPF1 page and did not find one. What Enkei markets instead is its own internal standard, Spec-E, described as tougher than JWL: a higher drop point in the impact test, and 20 per cent more cycles in both the rotary bending fatigue and dynamic radial fatigue tests than JWL requires.
Read that precisely. It is a claim that Enkei’s internal testing exceeds JWL’s thresholds. It is not a statement that a given RPF1 part number carries the JWL mark, which is what matters for Japanese road legality on a Japanese-registered car.
Enkei is a major Japanese manufacturer and an OEM supplier, and marking its Japanese-market wheels to JWL would be entirely normal practice. But we could not confirm it from the page we read, so we are reporting what we found rather than what we assume. If you are buying for a car that must pass shaken, check the wheel itself.
No Published Load Rating
Enkei’s specification table has no load-rating column, and we could not find a per-size figure in kilograms anywhere on the pages we read.
For most road cars this is academic. It stops being academic on a heavy vehicle, a van, or anything carrying weight — worth reading alongside our load rating guide.
RPF1RS, and the RPF2 That Does Not Exist
Enkei currently sells RPF1RS, described in its own copy as everything you like about the RPF1 with a deep face and a large lip added. Made in Japan, offered only in 18×9.5 to 18×11, in silver and matte dark gunmetal, using the same MAT process.
It reads as a companion for people who want the wide-lip look, not a replacement. The RPF1 remains a current product.
There is no RPF2 anywhere on Enkei’s site. If you see one advertised, that is somebody’s invention.
The OEM Context
One thing that gets lost when the RPF1 is discussed as a budget wheel: Enkei is not primarily an aftermarket company. Its own corporate page states the group supplies all the largest Japanese car manufacturers and General Motors in the OEM market, and it has been McLaren’s Formula One wheel supplier since 1995 — currently magnesium, with the arrangement renewed for 2026.
Same company, same process knowledge, behind a wheel that costs less than most brake discs.
A Note on Sourcing
We checked whether the site we read is genuinely Enkei’s. It is: the domain is operated by Enkei International, listed on Enkei’s own corporate page alongside the head office and the manufacturing company in Japan.
We check this every time now, because we found while researching another brand that the domain most English-language writing cites as that manufacturer’s official site is actually an authorised dealer. The distinction changes how much weight a specification carries. In Enkei’s case, the domain is the manufacturer’s own.
The Japanese-language Enkei product page for the RPF1 returned an empty body on two attempts, so everything above comes from the group’s English catalogue site rather than the Japanese one.
What We Could Not Verify
- An explicit JWL or VIA marking statement for the RPF1.
- Any published load rating in kilograms.
- Weights for the sizes Enkei’s own table lists as N.A.
- The Japanese-language RPF1 page content, which did not render.
- Whether RPF1RS is officially positioned as a successor or a permanent companion.