Forged vs. cast vs. flow-formed wheels: a breakdown for the Cybertruck
Three methods, different results
Aftermarket wheels are made by one of three methods: casting, flow-forming and full forging. Each gives the metal a different internal structure, and that structure is a major factor in how much load a wheel of a given weight can carry.
None of the three is the wrong answer for every truck. The useful questions are how they compare on strength, weight and price, and what your truck asks of its wheels. Everything below is something you can check on a spec sheet.
Cast wheels
Cast wheels are poured into a mold. Molten aluminum fills the mold, then cools and solidifies into the shape of the wheel. It is the lowest-cost of the three methods.
As the metal cools, it contracts unevenly, and small voids can form inside it. That is why a cast wheel can contain porosity. To carry the same load, a cast wheel generally needs more material than a forged one.
Flow-formed wheels
Flow-formed wheels have a cast center with a pressure-rolled barrel. The process starts with a cast wheel blank. The barrel is then spun against rollers, which stretch and compress it to its final width and thickness. Some brands market this as “rotary forged”, but only the barrel is worked; the center stays cast.
That rolling makes the barrel stronger than cast, while the center, spokes and face keep their cast structure. A flow-formed wheel sits between the other two methods.
Forged wheels
Forged wheels are pressed from a solid billet. A billet of aluminum alloy is pressed into a near-net shape and then machined into the finished wheel. Pressing solid metal gives a dense, continuous grain through the whole wheel, not only the barrel.
Side by side
| Cast | Flow-formed | Forged | |
|---|---|---|---|
| How it’s made | Poured into a mold | Cast center, pressure-rolled barrel | Pressed from a solid billet, then machined |
| Structure | Can contain porosity | Rolled barrel, cast center | Dense, continuous grain throughout |
| Strength for its weight | Lowest | Middle | Highest |
| Price | Lowest | Middle | Highest |
What to ask before you buy
- Alloy and temper. Xolaris: 6061-T6, typical tensile strength 45 ksi.
- Process. Xolaris: fully forged, one-piece monoblock.
- Per-wheel load rating. Xolaris: 3,600 lb on every wheel.
- Fit. Xolaris wheels are hub-centric: they center on the hub, with no adapter rings.
Why this matters for the Cybertruck
Load comes first. Tesla’s owner’s manual lists the Cybertruck’s gross axle weight ratings. The highest rear rating, on the all-terrain Premium All-Wheel Drive and Cyberbeast, is 5,247 lb, about 2,624 lb per wheel. Whatever the method, check a wheel’s per-wheel load rating against that figure.
Forged gives the most strength per pound of the three methods. The right choice depends on the load you carry and your budget, and every figure above is one you can check before you buy.