5.7-liter Hemi V-8
For more than a decade, the largest gasoline engine available on Ram HD trucks has been the 5.7-liter Hemi V-8, with customers needing greater power and torque stepping up to the Cummins turbodiesel I-6 engine. While a diesel is a natural choice in a larger, heavier truck, there are still a number of customers who would like a gas-powered option for cost or convenience.
We've found the 5.7-liter Hemi in the Ram 2500 to offer adequate power for most situations, but with Ford and General Motors offering 6.2-liter engines in their truck lineups, the 5.7-liter Hemi is starting to look like the runt of the litter. All that could change for the 2014 model year. Chrysler news and enthusiast site Allpar is reporting that the 2014 Ram HD trucks could get a version of the 6.4-liter Hemi used in the SRT models of the Dodge Charger, Challenger, Chrysler 300, and Jeep Grand Cherokee.
392 Hemi V-8 Engine
However, it's expected there will be significant changes to the engine for HD truck duty. Horsepower, torque, and compression ratio are all expected to be down from the high-output SRT version, but the engine should still make well over 400 hp and 400 lb-ft of torque. The cylinder deactivation offered on 6.4-liter SRT models equipped with automatic transmissions may remain, and it will likely be offered exclusively with a six-speed automatic. It's unknown if the transmission will be the 66RFE six-speed transmission currently offered on gas-powered 2500 models, or the new Aisin six-speed transmission mated to the Cummins.