11th May 2018
It has been four years since Ford introduced a redesigned F-150 pickup that had shed hundreds of pounds over the previous truck. And now, at the 2018 Detroit auto show, General Motors is doing the same, using a much different road map to lose those pounds.
While Ford turned to an aluminum-intensive body and structure, underpinned by a high-strength steel frame, GM followed what it terms a mixed-materials strategy.
That meant considering mass at every single step of the way in designing these trucks, chief engineer Tim Asoklis told C/D at an official introduction of the 2019 Chevrolet Silverado 1500, just before the kickoff of the Detroit show. “When you go down this path, there’s no one silver bullet,” he said. “It’s a combination of, from bumper to bumper, looking at every single element and asking, ‘How do I optimize it?’
“We took a real surgical approach.”
Using this rather sports-car-like strategy—which is now being applied throughout GM’s vehicle-development process—the team managed to cut 88 pounds from the body and another 88 from the frame. Anything that slams is aluminum—the hood, the doors, and the incredibly light-feeling, easy-closing tailgate (with available power closing)—while the body structure is all steel.
Patches Are Good
The frame is built of high-strength steel and was modeled with computer-aided design (CAD) to be strategically thicker only where it’s needed for loading, via tailor-rolled blanks and other methods—achieving a 10 percent gain in torsional rigidity. The same is true on the body with the high-strength steel, explained Asoklis. “There, you have tailor-welded blanks, so where you need high strength, you put it. Where you don’t, you don’t.”
GM won’t talk about carbon fiber for the cargo bed in any version of the Silverado—at least not yet. Underneath, though, it takes advantage of the Corvette’s composite transverse leaf-spring technology to save another 24 pounds. A new roll-formed, high-strength steel bed floor is 1.5 times the strength of the previous one—500 megapascals, versus 340 previously—and it has 12 stationary tie-downs that are double the strength of the ones on the previous truck. Another set of nine removable tie-downs will be offered as an accessory. The automaker also now stamps the bed as two pieces. That saved weight and allowed engineers to maximize bed space, with up to a 23 percent increase.
The cabin wasn’t exempt from weight-savings scrutiny. “The reduction of mass in the seat structure is significant as well,” Asoklis noted. Its slimmer design accommodates a felt-lined cargo tray in crew-cab models. It might also very well accommodate a battery pack, although GM hasn’t said anything about hybrid versions yet.
Read the full article at www.caranddriver.com.