[PSB]

I've never run an engine with hypereutectic pistons, but here's my understanding of the difference:

Hypereutectic pistons are much more brittle than forged pistons and are prone to disintegrating under severe detonation. They are harder, can be made to tighter tolerances, and cheaper than forged pistons.

A reasonably well tuned, naturally-aspirated engine should never see the kind of detonation that would cause a hypereutectic piston to fail. However, in an engine running nitrous or a large supercharger or turbo, detonation is much more likely to happen.


Pete