Although full-size pickup trucks remain wildly popular in the US, new emissions laws are requiring improved fuel economy figures. There are several ways to accomplish this, among them switching from steel to lightweight aluminum bodies, as Ford has done with its F-150, in addition to using new diesel and turbocharged engines.

All three Detroit automakers have done the latter, and Ram has even revealed a mild hybrid system for its 1500. For its part, Chevrolet recently launched the new turbocharged four-cylinder Silverado. This engine should be more efficient than the previous generation V6, right?

It is, but not by very much – and according to Automotive News GM wants us to ignore that for now. "I don't think we're done with the fuel economy piece yet," said Tim Herrick, executive chief engineer of GM's full-size trucks. "We learn more and more every day." The EPA has rated GM's new turbo 2.7-liter four at 20/23/21 mpg city/highway/combined.

On the plus side, the city rating is up by 13 percent, but the combined rating is only 1 mpg more than the outgoing 4.3-liter V6. But again, GM wants us to ignore that. Development is ongoing and GM is confident the fuel economy figures will certainly improve. Ford's 3.3-liter EcoBoost V6 and Ram's 3.6-liter V6 paired to that mild hybrid system both achieve 22 mpg combined, which is comparable to GM's new turbo four's equivalent rating.

However, the former two engines offer up to 25 and 26 mpg highway, and that's where GM needs to focus. GM does point out that EPA rating don't always tell the whole story because real-world fuel economy is typically better than what ratings claim. Above all, this new engine is an improvement over its predecessor and, at the very least, matches comparable V6 ratings from the competition.

"Don't look at the label," said Herrick. "We're as good or better than them in every step." GM has so far invested four years of work into this engine and like with any new product, improvements are expected.