Fiat-Chrysler is developing a straight-six cylinder engine for Jeep and Ram to replace the Hemi V8. That’s news in itself but there is a lot more going on. The rumor of a straight-six popped up on Allpar a few years ago. It is confirmed by various patents applied for as discovered by Mopar Insiders, and from Chrysler engineers listing the engine on resumes.

Straight-six engines are usually restrictive because they tend to be longer, but not this one. It is based on the GME “Hurricane” four-cylinder. In fact, many components from the GME are used in the previously codenamed “GME I-6”. Now it is called “Tornado.” Additionally, it is said to be able to be built with existing assembly plant production equipment.

“Tornado” Straight-Six Single- and Twin-Turbo

The Tornado engine would be compact, under 3.0-liters, featuring forced induction. It would utilize both a single- and twin-turbocharger setup. With Fiat-Chrysler’s eBooster system the engine could be a punchy replacement for both the current Hemi V8 and both 3.2- and 3.6-V6 Pentastar engines.  

The eBooster system uses electricity to aid in reducing turbo lag, especially in large turbo applications. Rumors are that the future twin-turbo version would use different cylinder heads. This would allow it to be used in higher-end Alfas, SRT performance models, and future Maserati products.

Under 3.0-Liters Eliminates Europe Taxes

The significance of having at least one version of the Tornado engine under 3.0-liters is because of European restrictions. There are many markets that have added taxes above three liters, so there is a demand for a smaller version to reduce use-taxes. 

The Fiat-Chrysler GME Hurricane four is currently found in the Alfa Romeo Giulia and Stelvio; and Jeep Cherokee, Wrangler, and Grand Commander. The Tornado is said to be only three inches longer than the Hurricane engine.

Straight-Six Architecture Popular Today

The development of an entirely new six-cylinder application was said to have been kicked off after direct-injection tests on the Pentastar V6 proved disappointing. Chrysler engineers decided an entirely new six-cylinder engine would need to be developed. Of course, many European manufacturers use the straight-six engine architecture with great success. Chrysler’s last straight-six was quietly put to rest in 2008 when the Jeep JK-series was retired.

With the apparent merger of Fiat-Chrysler and PSA in the works it will remain to be seen how it will affect the Tornado’s future roll-out and model applications. Initial rumors suggested Jeep would be the first to get it. That makes sense because it would probably be manufactured at one of Dundee, Michigan, assembly plants. This is close to Toledo, Ohio, where Jeep Wranglers are produced.

The Trenton, Michigan, assembly plant would also assemble the high-performance versions. It is currently the source for SRT V8 and higher quality engine applications.  These are only guesstimates because actual production could be years into the future.