Jeep and RAM ready for life without HEMI V8

Stellantis is primed to finally pension off its third-generation HEMI family of V8 engines after 18 years in production.

This follows reports of an all-new turbocharged 'Tornado' inline six-cylinder surfacing on the car-making group's official website.

Initially posted on Stellantis' powertrain blog Stellpower, but now deleted, the company referenced the all-new '3.0-litre GME T6' inline six-cylinder and confirmed it would be assembled at its Saltillo plant in Mexico.

No further details or specifications were released, but its arrival is believed to be imminent.

It is expected to replace the 5.7-litre HEMI V8 as well as the much mightier 6.2-litre Hellcat and Demon versions, plus the 6.4-litre '392' derivative used in the latest V8-powered Jeep Wrangler.

Instead of dropping the V8 altogether, it's thought the new inline six-cylinder will be introduced gradually – except in Europe, where Euro fleet average CO2 emissions will force the rapid adoption of the new family of sixes.

To meet ever-stricter emissions, it's almost certain Jeep models will need to embrace electrification.

Plug-in hybrid versions are also expected to be offered with the new inline sixes.

The first model likely to benefit from the all-new powertrain in Australia is the fifth-gen Jeep Grand Cherokee, with the 3.0-litre inline six set to replace the ageing 3.6-litre Pentastar V6.

It's already been confirmed Australians will miss out on the V8 offered elsewhere.

Tracing its history back to the early 1950s, the HEMI V8 takes its name from a hemispherical cylinder head that was invented to provide an enhanced surface-to-volume area for a more efficient burn.

The most powerful supercharged 6.2-litre HEMI V8 produced up to an incredible 603kW and 972Nm of torque under the bonnet of the fearsome Dodge Challenger SRT Demon – channelling all that might to its rear wheels.