Second, it's a way to downsize without stepping down to a four-cylinder. Chevrolet is taking a risk with its new Silverado-bound 2.7-liter Tripower turbo-four, and whether consumers will bite remains to be seen. Meanwhile, buyers seem comfortable with full-size pickups powered by six-cylinders. Allpar suggests that an FCA-designed inline-six could displace as few as 2.9 liters to conform with European regulations, though we imagine the line of engines would offer a number of displacement options -- some of which could be suitable for SUVs and trucks.
There are potential packaging advantages, too: A straight-six would be lighter and narrower than a V-8, and a compact head design patented by Chrysler a while back could shave off some of the height associated with inline-six engines. Remember, the storied and darn-near-bulletproof Chrysler Slant Six, built from 1959 to 1983 (for cars) and 1987 (for trucks), was so named because it was tilted on its side to better fit in an engine bay.
On the other hand, it’s hard to imagine a straight-six working with anything other than a rear-wheel-drive (or rear-biased all-wheel-drive) vehicle. But while the inline-six doesn’t lend itself to transverse-mounted front-wheel-drive applications, it could work in everything from luxury sedans to pickups, both full- and midsize.
There’s something special about an inline-six. I just drove a Mercedes-Benz CLS450 with the new 3.0-liter turbocharged M256 engine, and it was a reminder of the smoothness and refinement that a straight-six offers -- something that no V-6 can match. In that CLS450, the inline-six was combined with Benz’s mild hybrid system for seamless stop/starts and extra-torquey launches. FCA’s eTorque mild hybrid system could provide the same sort of functionality; it worked well on the 2019 Ram 1500 we drove and could pair nicely with a hypothetical inline-six, as well.
And an inline-six’s smoothness isn’t just good for luxury vehicles. Its gracefully delivered torque would be welcome in everything from family-haulers to pickups (which, at the top of the range, are practically luxury vehicles in their own right these days). It’s a versatile configuration, which is why it used to be common. Because everything old is new again, it may be time for this venerable engine to become (slightly more) common once more. I'm not holding my breath for an impending announcement but I'm very curious to see where FCA goes with this.