In September, Allpar reported that that clues being dropped at Fiat-Chrysler headquarters, in the carmaker's factories, and on engineer résumés pointed to the development of an inline six-cylinder engine. The site has just proclaimed the rumor is reality, writing that the straight-six, "turbocharged to meet or beat 5.7 Hemi power ratings, with a smoother torque curve, is on the way." The motor's first outing is expected to be either the next-generation Jeep Grand Cherokee, debuting perhaps next year, or the Jeep Wagoneer, debuting in 2020 or 2021.

"Tornado" is the purported codename for the power plant said to be just under three liters in displacement, expanding the family begun with the Global Medium Engine 2.0-liter turbo codenamed Hurricane. Engine bay constraints and a long use horizon mean engineers won't simply add two more cylinders to the GME, however. Allpar says the brief is to keep the Tornado GME-T6 — the alphanumeric for "turbocharged six" — no more than three inches longer than the Tigershark 2.4-liter four-cylinder. That means "major design changes" that could include a space-saving head, more closely spaced cylinders, and no cylinder liners. An FCA division called Comau could be called on for its "SmartSpray" plasma lining technology.

Allpar muses that the standard version of the engine for Chrysler, Dodge, Jeep, and Ram could get a single twin-scroll turbocharger. Performance trims for Alfa Romeo and Maserati could get different heads and maybe twin turbos, an SRT version might also get both those tweaks. History shows that the Italian versions would make changes to the block, as well. Even so, the Tornado would be less expensive than any Ferrari-supplied V6.

A straight-six would put FCA in company with current adopters BMW and Mercedes-Benz, future users like Jaguar, and perhaps Aston Martin. The engine would span the widest range of use cases in the U.S. carmaker's portfolio, though. Potential applications include being a base engine for Ram trucks, serving double duty as a base engine and 5.7-liter Hemi replacement for the Dodge Charger and Challenger, working in the high-end Jeeps, and as a properly hot trim — with Ferrari-designed heads — in the luxury Italian sports cars. The Alfa Romeo Giulia begs for just such motivation to fill the gap between the 280-hp, $42,695 Ti Sport RWD and the 505-hp, $73,700 Giulia Quadrifoglio RWD. And a twin-turbo inline-six in a Maserati Alfieri would stack up nicely with the Germans.

Said to be undergoing durability testing now, we probably have to wait a bit longer for more official information.

The site has just proclaimed the rumor is reality, writing that the straight-six, "turbocharged to meet or beat 5.7 Hemi power ratings, with a smoother torque curve, is on the way." The motor's first outing is expected to be either the next-generation Jeep Grand Cherokee, debuting perhaps next year, or the Jeep Wagoneer, debuting in 2020 or 2021.