You can blame the Ford Expedition for the change to independent rear suspension (IRS) rather than the current SUV's solid axle, probably. One source said Chevy wouldn't have fit the more expensive unit if the Expedition, which features an independent rear end and a high-tech turbocharged engine, had made less of a splash. But it did. We've raved about it at launch, and the next time we drove it – so Chevy has some serious competition in this segment for the first time in a long time.
Of course, the IRS could've been in the works all along. The next Chevy Silverado rides on the next-generation truck chassis, called T1, and the Suburban will ride on a variant of that chassis. The IRS could have been baked into the product plan a long time ago, mirroring the relationship between the body-on-frame Ford Expedition and its solid-axle F-150 counterpart.
Frankly, it doesn't much matter if this is a reactionary move or not – while solid axle roadholding and ride quality have improved drastically over the years, an independent rear setup offers more of both and is generally a huge benefit to the average consumer.
We expect the engine options to closely mirror the new 2019 Silverado, and yes, that could mean a 2.7-liter turbocharged inline-four in a Suburban.