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.

A couple notes about our test procedures: Unfortunately, we couldn't get all four trucks with exactly the same equipment. As you will see, there are two different axle ratios, 3.55:1 and 3.73:1; two trucks are rear drive; and one has a shorter wheelbase. Associate editor and certified tech nerd Mike Febbo made the following observations: All graphs represent the trucks being tested in second gear. The high and low run were thrown out and one of the remaining runs was chosen as representative. We were surprised by just how consistent the engines dyno-ed. Power and torque varied only by a few percent from pull to pull. It was determined that third-gear pulls would be significantly longer, and heat soak would be higher on the dyno than in real-world conditions with proper airflow.

All trucks began with at least three-quarters of a tank of 87-octane gasoline, the minimum requirement for all engines tested per Ford. A SuperFlow eddy current dyno was used for testing all trucks. (Eddy current dynos generally show lower numbers than inertia dynos.) Although it is possible to theoretically calculate crank horsepower numbers from wheel horsepower numbers, we're using the wheel horsepower numbers to measure the trucks against each other and not against factory claims.