[ByronRACE]

Hypereutectic pistons work FANTASTIC in perfectly tuned engines that never (ever) detonate. They grow/shrink less, wear like iron, are plenty strong, etc.

That said, racing engines and/or high performance engines that are played with, tweeked, run on pump gas, beat on, etc...have no business running hypereutectics. They are a brittle piston that shatters if the engine pings (detonates). Seen MANY dead hypereutectics on engines that were allowed to rattle. Even a little rat-tat-tat once in a while will kill them.

I would personally choose hyper over cast any day of the week, and hyper over forged for a ho-hum non-agressive engine that I intend to put 200K miles on in a street car. But, for a race/play toy, no way...go Forged. The first time the wife puts 87 in it, or you get a bad tank of gas, it'll rattle...and with Forged, you have a second chance.