1965 Chevrolet Impala on 2040-cars

Auto blog

Submit your questions for Autoblog Podcast #321 LIVE!

We're set to record Autoblog Podcast #321 tonight, and you can drop us your questions and comments regarding the rest of the week's news via our Q&A module below. Subscribe to the Autoblog Podcast in iTunes if you haven't already done so, and if you want to take it all in live, tune in to our UStream (audio only) channel at 10:00 PM Eastern tonight.
Discussion Topics for Autoblog Podcast Episode #321
Unibody Ford Ranger replacement

Why an independent rear suspension for GM's new, full-sized SUVs wasn't easy

A Motor Trend report last month laid out how Cadillac's 4.2-lier twin-turbo Blackwing V8 could be an orphan due to cost concerns in the GM empire. Last-minute chassis changes to Cadillac's new sedans and XT6 crossover led to engine bays that couldn't fit the Blackwing. On the SUV side, according to the report, the new independent rear suspension for big people haulers cost so much to implement that GM ruled out reworking the Escalade to accept the Blackwing. At least one commenter rightly asked how could a suspension swallow that much money. A new piece in Motor Trend has the answer. The excellent Alissa Priddle spoke to Tim Herrick, GM's executive chief engineer for full-size trucks, about why the clean-sheet IRS cost "multimillions of dollars."  First, GM would need to build a new body shop at the Arlington, Texas plant that assembles the automaker's big SUVs to stamp the numerous wholly new parts and panels accommodating an IRS. Then GM would need to design and pay for a new assembly process. On top of those up-front costs, there was the incremental cost of the four-link IRS components being more expensive than those in the trucks' former leaf-sprung solid axles. Herrick endured so many rejections for so long that he remembers the date and time when he got approval for the new unit. He said it came down to a meeting where he told a higher-up, "I'll make you a deal: If we get to the reveal, or if we launch this and you think this was a dumb idea, I'll hand you my badge and let you walk me out." Head to Motor Trend to read the full story. Based on Herrick being on stage to help present the new SUVs to the press, and on our First Ride in the new Chevrolet Tahoe and Suburban at GM's Milford Proving Grounds, it appears this will have a happy ending for all involved. Furthermore, since Herrick worked on the T1 platform that supports the big SUVs as well as the light- and heavy-duty pickups, he understood the demands on the commercial side, too. That could be why when Roadshow asked Tim Asoklis, chief engineer of the Tahoe and Suburban, if the new IRS could endure life in the Chevrolet Silverado and GMC Sierra, Asoklis answered, "Oh, absolutely." Related Video:    

Chevrolet Silverado, GMC Sierra could get independent rear suspension

The Chevrolet Silverado and the GMC Sierra could reportedly receive a variant of the four-link independent rear suspension found under the new Tahoe and Suburban. While that's not a surprise, a recent report suggests electrification, not comfort, convinced General Motors to make the change. Replacing the time-tested solid rear axle with an independent suspension will improve comfort, handling and off-road prowess, while adding weight, and likely making the trucks a little bit more expensive. It's a fair trade-off, but GM Authority learned the real reason for the swap is that at least one of the pickups will spawn an electric model, and it's more difficult to package a bulky battery pack around a solid rear axle. The independent rear suspension takes up far less space, even if it has more moving parts. General Motors will build its first regular-production electric pickup on an evolution of the Silverado's T1 platform named BT1, according to the same source. The b stands for -- you guessed it -- batteries. The firm reportedly doesn't want to make two suspensions for cost reasons, so the independent setup will come standard regardless of whether the truck runs on gasoline, diesel, or electricity. As a bonus, Chevrolet and GMC could choose to offer their T1-based trucks with Magnetic Ride Control or an air suspension, options available on the 2021 Suburban and Tahoe. The independent rear suspension will also find its way to the next-generation GMC Yukon due to be revealed January 14, and to the 2021 Cadillac Escalade scheduled to make its debut February 4. The long-rumored, born-again Hummer will get it, too, because it will arrive as an electric model built on the BT1 platform. It's worth noting none of this is official, and General Motors has remained quiet about what's next for its new suspension design, and what will be under its electric truck's sheet metal. If the GM Authority report is accurate, the Silverado (pictured) and the Sierra could ditch their solid rear axle for the 2021 model year. The change will likely be accompanied by other tweaks inside and out. Featured Gallery 2019 Chevrolet Silverado 1500 View 16 Photos Chevrolet GMC Truck