Monster V-8 Showdown: 2020 Chevrolet Silverado HD Vs. 2019 Ram HD

Buyers interested in the heavy-duty truck market — meaning three-quarter-ton and one-ton pickup trucks — are enjoying what could be called the Golden Age. All three of the big-truck manufacturers are offering all-new HDs for the 2019 or 2020 model years. Since pickups in this class are about heavy hauling and towing, that means their big motors are getting updates as well.

Both Ford and GM have all-new or replacement gasoline V-8s for their HD truck lineup; as we write this, we’re collecting more information on Ford’s new 7.3-liter gasoline V-8. We’ll have more on that one later. In the meantime, here’s a quick comparison of similarly sized gas engines in two HD competitors: the 6.6-liter V-8 that powers the 2020 Chevrolet Silverado 2500/3500 (and 2020 GMC Sierra 2500/3500), and the 6.4-liter Hemi V-8 found in the 2019 Ram 2500/3500.

Ram’s 6.4-Liter Hemi V-8

The 2019 Ram 2500/3500 lineup will offer just one gas engine option and two power levels for the 6.7-liter Cummins inline-six-cylinder. The 6.4-liter Hemi V-8 carries over from 2018, but it’s paired to an all-new eight-speed automatic transmission (the TorqueFlite 8HP75), which will significantly change the gas engine’s performance. The 6.4-liter engine uses a cast-iron block with aluminum heads, while pushrod-operated overhead valves (two per cylinder) help it breathe. The heads include a partial hemispherical-shaped combustion chamber and dual spark plugs with a 10.0:1 compression ratio to provide a better, more complete fuel burn, achieving 410 horsepower at 5,600 rpm and 429 pounds-feet of torque at 4,000 rpm. The 6.4-liter Hemi offers fuel-saving technology with a wider range of cylinder-deactivation phases that allows it to run longer in V-4 mode when demand is low; additionally, there is a deceleration fuel shut-off feature when slowing down or coming to a stop.

GM’s Direct-Injection 6.6-Liter V-8

The all-new fifth-generation direct-injection gas V-8 will replace the stout but aging (20 years old) 6.0-liter V-8 in the 2020 GM heavy-duty trucks. The new, larger engine will be available in the Chevrolet Silverado 2500 and 3500 pickups as well as GMC Sierra 2500 and 3500 models as the gas alternative to the carryover turbo-diesel 6.6-liter Duramax V-8. The all-new engine will be mated to a modified version of the carryover 6L90 six-speed automatic transmission. The new engine uses a cast-iron block, aluminum heads, and forged connecting rods and crank. The 6.6-liter uses an overhead valve and pushrod system with two valves per cylinder to get as much power as possible at the lowest rpm possible. What’s unique about this engine is that it’s the only gas direct-injection engine (running a 10.8:1 compression ratio) in the HD class. It was chosen to deliver a more precise and efficient fuel shot into the combustion chamber at relatively high pounds-per-square-inch. GM told us the factory ratings are 401 hp at 5,200 rpm and a whopping 464 pounds-feet of torque at 4,000 rpm. GM decided not to offer any fuel-saving technologies on the engine beyond what’s provided through the upgraded parts and material coatings. GM is introducing an all-new active oil pump that allows access to various amounts of oil reserves inside the aluminum oil pan, meaning it can bring the engine up to operating temperatures faster as well as cool more oil down during extreme work situations.

The Winner?

Since we haven’t driven the new GM V-8 yet and information about how the Ram 6.4-liter Hemi V-8 performs is embargoed until Feb. 28 — we’ll share our driving impressions then — choosing a winner becomes theoretical. It will be interesting to see how these two engines stack up in direct competition since the Ram Hemi has more horsepower (410 versus 401), but the new GM small-block gas engine offers substantially more torque (464 versus 429 pounds-feet).

Cars.com’s Editorial department is your source for automotive news and reviews. In line with Cars.com’s long-standing ethics policy, editors and reviewers don’t accept gifts or free trips from automakers. The Editorial department is independent of Cars.com’s advertising, sales and sponsored content departments.