Engine downsizing comes with downside

Downsized turbocharged engines continue to grow in popularity because they offer impressive fuel efficiency and squeeze out the power. But there’s a downside.
Their high-compression nature in certain circumstances can damage engine parts, sometimes catastrophically, says Joachim Wagenblast, director of R&D-engine systems and components for engine supplier Mahle USA.
He cites broken piston rings, cracked off tops of pistons and bent connecting rods.
The culprit is called low-speed pre-ignition, or LSPI. It is an abnormal combustion phenomenon that occurs before the normal spark-plug ignition and is not widely known. This article first appeared in WardsAuto.