TheDrive.com tells us that GM Uses Diesel Tricks to Make Four Cylinder Truck Engines Tougher…
The result is an engine that can withstand being abused for literally weeks on end—which is how Luchansky says GM tested the 2.7L. Those are his words: GM dyno-tested it at wide-open throttle “for weeks” straight, making prototypes’ pistons glow and wrist pins discolor purple from the heat. GM’s also torn down engines bought back from customers who drove without oil, all to find failure points whose fixing has already significantly lengthened the engine’s service life. In fact, the upgrades have meant that even extreme cases might not even wipe off the manufacturing sticker from the inside of the bearing.
GM’s 2.7-liter turbo four-cylinder truck engine cutaway. James Gilboy
