They’re arguably the two most popular engines in the pickup truck segment, and each one currently enjoys legendary-like status among its followers. We’re talking about the 3.5L EcoBoost in the Ford F-150 camp and—of course—the 5.7L Hemi that hails from under the Ram umbrella. These two half-ton power plants differ in so many ways it’s hard to count them all—yet they both turn out similar power figures, return comparable fuel economy and provide their respective brand’s best-selling models their peak towing capacities. It’s time we got serious about comparing the two most recognizable engines in the world of half-ton trucks.
For Ram, the Hemi has been the brand’s half-ton alpha engine since 2003, when it replaced the aging 5.9L (360 ci) Magnum V-8. But it didn’t require much convincing (or Hemi commercials…) to get Ram buyers interested in the 5.7L. The Hemi debuted with a rating of 345 hp—a big number 19 years ago. Throughout the years, it’s gained variable valve timing, higher compression and more horsepower, which has grown to its current 395 hp output. As for the twin-turbo 3.5L EcoBoost V-6, it arrived in the ’11 F-150 and immediately established itself as a threat to the thumping, naturally aspirated V-8 gas engines that’d ruled the half-ton roost for decades. It too has seen substantial increases in horsepower as well as a bump in compression over the past decade.
Now, the latest versions of the two go head-to-head below. Which is better, the high-tech, boosted V-6 or the thumping overhead valve V-8?
3.5L EcoBoost: The Small-Displacement, Boosted V-6 That Changed The Game
Ford recently celebrated its 45th consecutive year of its F-series line being the best-selling vehicles in America, and the 3.5L EcoBoost is a big part of that accolade. The 213 ci, aluminum block and heads, 60-degree V-6 sports chain-driven, dual overhead cams (DOHC), twin independent variable cam timing (TiVCT) and four valves per cylinder. Thanks to its high-pressure direct injection fuel system and twin-turbocharging, the 3.5L EcoBoost belts out an incredible 400 hp at 6,000 rpm and 500 lb-ft of torque at 3,100 rpm (non-hybrid, 2021 figures). Having 500 lb-ft of torque available at such low rpm provides relentless, almost diesel-like acceleration off the line.
5.7L Hemi: The V-8 Gas Engine That Made Ram A Contender Again
Shortly after the turn of the century, Dodge’s Ram 1500 line offered the least potent engine options among The Big Three. All of that changed one year after Dodge changed the Ram’s body style (third-gen), with the arrival of the 5.7L Hemi V-8. The Hemi packed 100 more ponies than the outgoing 5.9L Magnum V-8 it replaced and its initial 345 hp and 375 lb-ft rating made it more than just a contender again in the half-ton class—it was out front. The 345 ci, iron block, aluminum headed, 90-degree V-8 utilizes an old-school, overhead valve (OHV), two valve per cylinder, single cam design and has made use of variable valve timing since 2009. The latest version in the Ram 1500 produces 395 hp at 5,600 rpm and 410 lb-ft of torque at 3,950 rpm.
Parallel Turbos (i.e. “True Twins”)
A big part of the 3.5L EcoBoost’s success in matching (and exceeding) the performance of much larger V-8 offerings is owed to its twin-turbo (parallel turbo) design. A true twin-turbo system, one turbocharger feeds each bank of the engine. Both chargers are K03 model, fixed geometry units from BorgWarner with water-cooled center sections. To prevent possible overspeed scenarios (where drive pressure exceeds a pre-determined threshold), both turbochargers feature electrically-actuated wastegates. Maximum combined boost production between the two turbos checks in between 16-18 psi from the factory. Boosted air is routed through an air-to-air intercooler prior to making its way into the heads.
Naturally Aspirated
Like many other V-8’s in Mopar’s lineage, the 5.7L Hemi gets things done with good old fashioned displacement. In terms of complexity, the Hemi is far simpler than the 3.5L EcoBoost, although the eTorque version of the powerplant adds a bit of new-age tech to the near-20-year-old engine design. The mild-hybrid technology, as it’s known, adds a crank-driven electric generator to the mix, which provides up to 130 lb-ft of supplemental torque, aids fuel economy and even makes regenerative braking possible.
Direct Injection
One big difference between the 3.5L EcoBoost (and the entire EcoBoost line, for that matter) is Ford’s employment of direct injection. This means of initiating combustion calls for higher fuel pressures and culminates in considerably more fuel efficiency and power production. This type of combustion calls for a different piston design than what you’ll find in most traditional fuel injected gasoline engines. Fuel pressure in the 3.5L EcoBoost ranges from 200 to 2,150 psi. Beginning in 2017, Ford coupled direct injection with sequential multi-port fuel injection on the 3.5L EcoBoost.
Sequential Multi-Port Fuel Injection
The 5.7L Hemi makes use of sequential multi-port fuel injection and a coil-on-plug ignition system. Hemi’s utilize 16 spark plugs, two per cylinder, with a coil pack over one spark plug and a conventional spark plug wire connected to the other one. The dual spark plug system is designed to curb emissions, with the second plug firing at the end of the power stroke. The latter results in a less complex catalyst being required downwind of the engine.
F-150 EcoBoost: More Towing Capacity & Faster
As the kings of their respective brands’ engine lineup, opting for the 3.5L EcoBoost in an F-150 or a 5.7L Hemi in a Ram 1500 is the only way to get maximum towing capability out of each truck. In Ford’s case, when the 3.5L EcoBoost (non full-hybrid model) and Max Trailer Tow Package are present aboard a 4×2 SuperCab with an 8-foot bed or a 4×2 SuperCrew 14,000 pounds of max towing capacity is on the table.
That’s a huge number for a half-ton pickup. While fuel economy is known to suffer when the 3.5L EcoBoost is towing heavy, performance-wise its broad torque curve makes it one of the best workhorse engines in the segment—and in fact we’d put it right behind the 3.0L I-6 Duramax and the 3.0L V-6 EcoDiesel in work ethic. Pitted against the Ram, a 3.5L EcoBoost-powered F-150 is the hands-down winner in any head-to-head acceleration test, with 0-to-60 mph times in the mid-5-second range and 13.9-second quarter-miles possible.
Ram 1500: A Close Second
While the Hemi doesn’t have the abundance of low-end torque on tap that the EcoBoost does, it has no problem towing at a late-model Ram’s max GCWR. Max trailer towing remains 12,750 pounds for a 4×2 Quad Cab Ram spec’d with a 6-foot, 4-inch bed. And although the Hemi is outperformed by the 3.5L EcoBoost in virtually every acceleration test, it still holds its own against Ford’s twin-turbo’d menace. Mid 14-second quarter-miles and high-5-second 0-to-60 mph times can be achieved in a Hemi-powered Ram. Acceleration and towing numbers aside, the old-school V-8 rumble of the Hemi is hard to beat. Who knows exactly what the future holds for the automaker’s gasoline V-8, but—as is evident in Ram’s year-end 2021 sales figures—right now Americans continue to buy them like hot-cakes.
Keyword: EcoBoost Vs. Hemi: Battle Of The Most Popular Half-Ton Truck Engines