The 2023 Chevrolet Colorado has ditched the six-cylinder and diesel engines entirely and now uses only the Silverado’s 2.7-liter turbo four. The switch has left truck buyers skeptical: Is there really a replacement for diesel displacement or torque? Does General Motors just ship trucks powered by gutless time bombs? Not according to the man who oversaw the engine’s development. In fact, he went so far as to call it one of the toughest engines GM has always built, and that’s saying something.
It would be hard to believe it came from anyone other than Kevin Luchansky, GM’s deputy chief engineer for powertrains. Speaking to the press for the new Colorado this week, Luchansky described the diesel-derived design elements and testing regime of what he calls “one of the longest-lasting engines GM has ever made. It’s very, very good.”
Even with Luchansky’s confidence, it’s important to understand what concerns truck owners in this lump. At 2,727cc, it’s second only to Ford’s 2.7-liter Ecoboost V6 for the smallest full-size pickup engine and third-smallest among midsize trucks. It has a relatively high compression ratio of 10:1, with boost pressures up to 27 psi. That translates to twice the cylinder pressures of a comparable naturally aspirated V8, like the 5.3-liter small-block that effectively replaces the larger Silverado.
That could mean eliminating problems out the wazoo, especially considering the 2.7L is designed to run on only 87-octane gas. But Luchansky was adamant that it will take anything you throw at it because he designed it with diesel engine tricks that help it hold up remarkably well in torture tests.
Although the 2.7L is nominally an all-aluminum engine (keeping the long-block weight down to 331 pounds), it actually has iron cylinder sleeves cast into the block during manufacture. It’s a more modern material, though, so Luchansky says it won’t wear out like many older cast iron blocks do.
Its pistons are also aluminum alloy, with machined heads to optimize the material’s properties and cast iron ring carriers to hold the rings at high cylinder pressures. Instead of the typical molybdenum-coated iron rings, the 2.7L uses diesel-grade steel rings with PVD coatings, reducing friction and slowing wear.
The four-legged extreme torque output of up to 430 lb-ft means it needs some serious bearings, too. That’s why Luchansky chose not to use usual bimetallic rod bearings, with aluminum alloy on a steel support, but trimetal with an added layer of copper alloy to remove more heat.
The result is an engine that can take abuse for literally weeks, which is how Luchansky says GM tested the 2.7L. Here are his words: GM tested it at wide open throttle “for weeks” on end, causing the prototypes’ pistons to glow and the wrist pins to turn purple from the heat. GM also tore down engines purchased from customers who were driving without oil, all to find failure points whose fixing has already significantly extended the engine’s life. In fact, upgrades have made it so that even extreme cases don’t even erase the manufacturing sticker from the inside of the pad.
“We’re now running 25 percent faster than before,” Luchansky said of the engine design improvements. “Over the years we’ve made things stronger and better. It’s one of the reasons we can push the torque as much as we can.”
Luchansky knows, however, that he can’t force this engine down the throats of truck buyers, and that he must establish a reputation on his own. “It just has to prove itself, and it’s proving itself,” he said, adding that GM has already sold more than 300,000 trucks with these engines, receiving overwhelmingly positive feedback.
“The people who own them, they love them,” Luchansky said. “If you talk to the dealers, they’re like, the 2.7L is rarely in service.”
But again, the real test will be out in the world, where people will miss oil changes and overload trailers. GM’s work will have to speak for itself, whether that means the 2.7L makes its way into people’s hearts or makes them appreciate the engine entirely. By the way Luchansky is talking about his baby, looks like we should just hope for the best.
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