2011 Ford F-150 Comparison: V-6 vs V-8
Brains Vs Brawn: What's Better -- High Tech or Big Displacement?
From the October, 2011 issue of Truck Trend / By Allyson Harwood
When this generation of Ford's F-150 was introduced for the 2009 model year, it was impressive enough to win Motor Trend's Truck of the Year honors. That was despite its one big downside: an aging lineup of engines, all three of which were V-8s. They included a two-valve, 248-horsepower, 294-pound-foot 4.6-liter V-8; another 4.6-liter V-8 with three valves per cylinder that put out 292 horsepower and 320 pound-feet of torque; and a 5.4-liter V-8 offering 310 horsepower and 365 pound-feet. Making things worse, the two-valve -- was backed by a four-speed automatic, and fuel economy wasn't good enough. Many different clues pointed to the same conclusion: It was time for new engines.
Fast-forward two model years, and all three V-8s have been swept aside. In their place are two V-6s and two V-8s, all with variable valve timing. All but one (the 6.2) feature all-aluminum construction, and all are backed by the same six-speed automatic. Fuel economy has improved across the board, except for the 6.2. And in what seems a major contradiction, power has increased as well: Even the base V-6 has more horsepower than the three-valve 4.6-liter, falling only 8 shy of the 5.4.
We wanted to know how these new engines perform, so we wrangled together four F-150s with four different attitudes: a 3.7-liter-V-6-powered regular cab STX, a 5.0-liter SuperCrew XLT, a 6.2-liter Harley-Davidson Edition SuperCrew, and a 3.5-liter EcoBoost SuperCrew Lariat. We took the quartet to the track in El Toro, California; on the road; and to the dyno at K&N Engineering, to see how the F-150 fares with the new engines. We also wanted to find out if the horsepower, torque, and fuel economy data match up with the manufacturer's numbers, and whether it makes sense to get a twin-turbo V-6 instead of a good old American V-8.
What The Dynomometer Tells Us
3.7-liter: V-6 The peaks and dips in the 3.7-liter V-6's torque curve were consistent in every dyno run. Torque peaked initially at 2400 rpm, then fell off and began climbing again to another peak at 4200 rpm. While previous engines would produce peak torque and then fall off, Ford's extra efforts in variable valve timing, Ti-VCT, has made the engine more efficient across the rpm range.
5.0-liter: V-8 As on the 3.7-liter V-6, the use of Ti-VCT spreads out the torque curve. While smoother on the V-8, definite peaks are apparent on the graph; unlike with the V-6, they are barely noticeable in real-world driving. While not the fastest truck in the test, the quickly climbing power curve makes it feel fast on the street. Downside is the need for higher-rpm operation when towing.
EcoBoost: The dyno doesn't provide enough resistance to get a realistic torque reading at the low end of the chart. The EcoBoost can accelerate past 2000 rpm before the turbos are producing full boost. On the road, with more resistance, the truck would likely produce more torque than indicated below 2000 rpm. The later spool-up also means less heat in the beginning of the dyno run, so the torque beyond that point might be slightly inflated.
6.2-liter: V-8 Based on a different, older family of engines than the 5.0-liter V-8, power and torque curves are nearly identical in shape on the 6.2-liter, just farther up the graph. Torque builds quickly below 3000 rpm, levels out, then starts to run up again up to a peak at 4500 rpm. On dyno and road, the V-8's behavior could be called angry. While EcoBoost and Coyote V-8 are silky smooth, the boss wants to jump out of the truck and bite someone at wide open throttle.
Torque: The torque curves for all four engines are fairly flat. The EcoBoost has the best of all worlds: flat curve, most torque, and lowest rpm at which peak torque was achieved.
Horsepower: EcoBoost engine had most power on the dynomometer, followed closely by the 6.2L, then the 5.0L, with the 3.7L closing.