PHOENIX — When you make big investments in a pickup to improve fuel economy — think Ford's aluminum-body F-150 or the mild-hybrid system on Ram's 1500 — you expect significant results.
So how does General Motors explain shifting to a four-cylinder turbo for its redesigned full-size pickups and getting little gain in combined EPA fuel economy ratings over the previous generation's V-6?
As a work in progress.
"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, during a Silverado media drive here. "We learn more and more every day."
Squeezing fuel economy gains out of pickups is never easy. Ford's 2015 aluminum F-150 with a then-new 2.7-liter V-6 initially gained up to 4 mpg combined, while Fiat Chrysler Automobiles' 2019 Ram 1500 with eTorque gained up to 2 mpg overall. Those gains don't sound big, given the billions of dollars invested, but in percentage terms, they are huge, and their environmental impact — as measured by federal regulators — is magnified by the trucks' enormous sales volumes.