Ford positioning its puny 3.5-liter twin-turbo EcoBoost V-6 atop the F-series lineup caused more than a few observers to choke on their chew. To see how the power structure shakes out, we lined up two nearly identical F-150s: one with the 5.0-liter V-8, one with the 3.5-liter twin-turbo EcoBoost V-6. Both are four-wheel-drive crew cabs with 5.5-foot beds. They pack the same six-speed automatic and 3.55:1 final-drive ratio. Aside from the turbocharged truck’s option to display a digital boost gauge, the interiors are indistinguishable. Even the paints are similar shades, just in case UV saturation affects weight. The EcoBoost F-150 did, however, come in 213 pounds heavier, in part due to its dual-pane sunroof and the FX4 package’s skidplates.
Unladen, the 5.0 trails the EcoBoost to 60 mph by a half-second, taking 6.3 seconds versus 5.8. With trailers in tow, that gap grows to nearly two full seconds. From behind the wheel, the difference is astounding. Not that this should come as a surprise: Ford rates the EcoBoost’s towing capacity higher than the V-8’s, and our four-wheel-drive V-6 is rated to pull 11,500 pounds to the V-8’s 9000. (We chose less than the maximum load to represent what these trucks are more likely to encounter in everyday use.)
Still, such a significant load shines an unforgiving light on powertrain weaknesses. Laden, the V-8 needs a lot more pedal travel and a lot more revs than the EcoBoost does. From cruising speed, if you roll into the V-8’s throttle, you just keep on rolling in deeper and deeper until the throttle is wide open, waiting for a few more mph. With more than three tons out back, even moderate acceleration calls for full throttle or nothing. Under partial throttle, the turbocharged six gets things done that the V-8 can’t.