Here's something to try, guys, after all you have nothing to lose!
Driving like a granny does not contribute to good fuel mileage contrary to popular belief. Fuel economy is determined by covering the maximum distance on the least amount of fuel consumption. That requires vehicle speed and reduced throttle opening.
Several years ago I was employed by a major home delivery company that was very interested in reducing fuel cost. A training program was developed and we were all sent to the center to learn this method of driving. On first run we were sent out in a vehicle with fuel flow equipment and a vacuum gauge and told to drive the way we normally drove. Well, as you can guess, we all were determined to "show em" and drove the coarse as gingerly as possible. Then, we did a second lap following the instructions of the teacher to the letter. Well, guess what, we covered the course in significantly less time and used over 10% less fuel as well. I have taken this method to heart since then and found better fuel economy in anything I drive from my hot rod to F150!
Most of our trucks have the instant mileage indicator system. Set yours so you can use it while you drive. It is similar to a vacuum gauge in that the lower the green bar, the lower your mileage. It also indicates average fuel economy as well and is a fabulous indicator of granny driving costing you fuel economy!
Now, the secret formula. First, make sure your tires are up to pressure. I don't mind a little harder ride so mine get inflated to max pressure all year round. I get phenomenal tread wear (or lack of) and the rolling resistance is reduced as well.
When driving in congested areas, avoid the packs. Time the lights so you are rolling as much as possible. Idling while stopped yeilds 0mpg! If you do get stopped, when leaving use half to 3/4 throttle and get up to speed asap. Don't jack rabbit, roll into the throttle gently and roll out immediately upon reaching desired speed. Now, if there's traffic in front, they will determine many factors here but when you're in control, make it happen. You will see when you're the leader of the pack, the pack will be far behind you as you leave.
Step two. Maintain steady speed. I use my cruise control even in traffic and in city driving as much as possible. You'll see in the instant indicator how effective this is. Speeding/slowing, what I call rubber banding, kills fuel mileage!
Step last. Coast whenever possible. Gauge the lights. When coming up on a stop sign or stale green light, cancel the cruise and let it coast down to speed or until you need to brake to stop or for traffic in front. Coasting yeilds maximum fuel economy and brings the average up fast! When using cruise in a hilly region, your truck will do this automatically.
In conclusion:
1) Properly inflated tires
2) Get up to speed quickly but not like a drag race
3) Maintain steady speed and time the lights to reduce stopping
4) Coast whenever possible or needed.
Give this a shot, guys, and let me know how it works for you!