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General Motors was set to debut a new inline six-cylinder engine for the Chevrolet Silverado and GMC Sierra pickups. It would compete with Ram’s Hurricane 3.0-liter, introduced this year. But now comes word that GM is scrapping those plans as it revs up electrification efforts. 

How much horsepower would the new Silverado 6-cylinder engine have had?

A royal blue 2024 Chevy Silverado EV RST electric truck
2024 Chevy Silverado EV RST | General Motors

The TT I6 truck engine was to be based on GM’s L3B 2.7-liter turbo-four, available in the Sierra and Silverado. GM has a “Cylinder Set Strategy,” part of its plan for creating the inline-six. Basically, it was adding another two inline cylinders to the L3B engine. Oh, and it was also adding another turbocharger, GM Authority reported.

Though GM never announced numbers, insiders said it was a 500-hp engine with 500 lb-ft of torque. The naturally aspirated Ram 3.0-liter Hurricane engine delivers 510 hp and 500 lb-ft of torque. So the numbers for both are similar. But one would’ve been twin-turbocharged, while the other is naturally aspirated.

What other inline 6-cylinder engines does GM have?

GM 2.7-liter I4 L3B turbo engine
GM 2.7-liter I4 L3B turbo engine | GM

Comparing the stillborn I6 to GM’s L84 and L87 V8s, they offer 355 hp and 420 hp, respectively. And torque numbers are 383 lb-ft and 460 lb-ft. So, as with the Ram Hurricane, GM’s I6 would have bettered its V8 siblings by a bunch. 

That wasn’t the first stab at an inline six-cylinder engine for GM trucks. Of course, its original inline-six backed Chevy and GMC trucks and passenger cars for decades into the 1970s. And in 2002, GM introduced an all-new I6 called the LL8 Vortec 4200. New Chevy Trailblazer, EMC Envoy, and Oldsmobile Bravada SUVs received this engine.

Later, it powered various other GM products, including the Saab 9-7X. The engine lasted until 2009 before the automaker killed the Vortec 4200, for two reasons. First, the platforms using the engine were no longer around. And second, GM decided to shutter the 4200 engine plant in Moraine, Ohio. The company used its Cylinder Set Strategy to also create three five-cylinder engines and four-cylinder offshoots of the Vortec 4200. 

Would the Silverado inline-6 have had more power than a V8?

GM has quite an array of six-cylinder engines, but they’re all V6 configurations and twin-turbocharged. Displacing 3.0 and 3.6 liters, they power various Cadillac models only. Ford and Toyota also have V6s but no inline-sixes. So, for now, and maybe for some time, the only inline six-cylinder engine, besides diesel, will be the Ram Hurricane

Insiders suggest that with the I6 off the table, further development will occur with GM’s 2.7-liter I4. And recently, the company announced it’s developing a new small-block V8 generation. So while GM dives headlong into electric-powered development, it isn’t giving up on gas-powered engines. And with all the buzz surrounding synthetic fuel as a replacement for gasoline, a zero-emissions internal combustion engine could become a much more marketable product into the 2030s. 


Overview: All 2023 Chevy Silverado 1500 Engine Options