mpg f150 ecoboost to lock out 6th or not

Howie3 wrote:
Great question. I have the same truck with 3.73 axle. My experience (though not scientific)is that I get better mileage at the lower RPMs in 6th gear, so if the truck will maintain 6th on its own, I let it do its thing. The exceptions would be a headwind, a slight uphill grade, or if I am travelling under 55 mph. In these cases the truck may tend to lug a bit, even though the low end torque maintains 6th gear. I then lock out 6th as it 'feels' better and the truck is more responsive and it's probably a little easier on the transmission. I don't think the difference in fuel economy would be significant in either case so I go with the most comfortable towing experience in each given situation. The Ecoboost is so quiet regardless of the gear.