Is Fiat Chrysler working on an inline-six?

1965 plymouth barracude 225 super six orange

Do you like smooth, even power delivery and inherent balance in an engine? Fiat Chrysler is reportedly working on expanding its four-cylinder Global Medium Engine (GME) into an inline-six that could replace some current applications of the Pentastar V-6 (and maybe even some V-8s).

That news comes from Mopar site Allpar, which speculates that this new engine—codenamed Tornado in reference to Jeep’s OHC inline-six from the ‘60s—will displace just under 3.0 liters. Part of the strategy there is apparently to minimize the displacement-based annual road tax many European countries levy on vehicles.

The current GME four-cylinder, at just under 2.0 liters, would come out at 2.99 liters assuming FCA adds two cylinders and maintains the current 84-mm bore and 90-mm stroke. The turbocharged GME 2.0-liter four-cylinder, codenamed Hurricane in its North American applications, can be found in the current Jeep Wrangler and Cherokee producing 270 horsepower and 295 lb-ft of torque. Simply multiplying those numbers by 1.5 to extrapolate what two additional cylinders could (very, very roughly) provide gives us 405 horsepower and 443 lb-ft of torque, which would certainly make for a potent engine in a car or SUV.

Slant-6 engine black and white
FCA
Slant-6 engine

Potential applications for the inline-six include the Jeep Grand Cherokee, which once upon a time used the venerable 4.0-liter AMC inline-six in its first two generations. The straight-six could also see service in the long-awaited Grand Wagoneer, as well as Ram pickups. And, given BMW’s long-time use of inline-six engines as Mercedes’ and Jaguar’s recent resurgence of the engine layout, Maserati or Alfa Romeo might want a powerful, smooth-running inline-six engine of their own. Perhaps with even better cylinder head flow and more boost? A boy can dream.

After decades of powering everything from Darts to Rams with the venerable and unkillable Slant Six, one of our favorite inline-sixes, the last Mopars to be powered by a gasoline straight-six were the 2006 Jeep Wranglers with the aforementioned AMC 4.0. We haven’t seen an American truck or SUV with a gasoline inline-six since GM pulled the plug on the Atlas 4.2-liter engines when Trailblazer and Envoy ended production in 2009. Of course, the Cummins diesel has kept the straight-six alive in 3/4- and 1-ton trucks, and GM plans to bring a 3.0-liter inline-six diesel to the half-ton 2020 Chevrolet Silverado and GMC Sierra.

Are we witnessing a straight-six renaissance? We’ll have to wait and see if these six-cylinder rumors pan out.