03' Regular cab, 4.6L, 2X4, 3.07 gears:

Ave: 17.5MPG
Best: 18.7MPG
Worst: 15.4MPG

I drive mostly highway (70%) and with a real light foot.

 

MGuimares,

Yes, I run a soft tonneau. As I posted, between the cover and taking it easy on my 90 mile commute, I went from about 16.5 to the best of 18.21. I honestly don't know if having the 235 tires and maybe the elevation being different has any bearing on the subject. I have axel code 19 which is 3.55 gears, right? Also noticed on the door sticker that the truck was new with the 235 tires. I thought stock was 245 or 255.

 

A tonneau is better than an open bed. I have an engineering paper describing tests of various types of tonneaus and they really reduce drag. Believe it or not, the best tonneau is a rear half tonneau.

 

I noticed that the back half of my soft cover gets pushed down at highway speeds. All of my friends with the soft covers have the same thing. Learn something new every day!

 

What you've seen is that the front half of the tonneau is in a turbulent mish-mash of air, while the air flowing over the roof drops onto the rear half. The engineering paper describes a drag reduction for an open front half and covered rear half. I think the open front creates a nice bubble of turbulent stagnant air to smoothly direct the air onto the rear half. A full tonneau helps, but not as much as just the rear half. Thanks for your real world input.

 

I have a camper shell on my truck, seems to help and its better than sleeping in a tent while on fishing, camping and hunting trips... Or if I, ahem, can't drive home some weekend nights for some particular reason.

 

1999 f150 ext. cab....112000miles..4.6 engine
with quaker state syn. 5w30 oil.....3.55 rear end....automatic

I just got back from a trip to the Grand Canyon that was 2066 miles round trip.

my truck is lowered 2-4 with 20 inch wheels

overall mileage was 19.9 mpg

 

You all are talking about tonneau cover, but for those of us that dont have them, does the ol' wifestale about dropping the tailgate on those long tripps do any good?

Peties3- where did you get that hood man, ive been looking for that one...how much did you get it for (just the hood, i know a paint guy)??

 

Dropping tailgate destroys the desired airflow across the bed. The turbulent but stagnant bubble behind the cab that blends the flow downward and rearward over the rear roof edge goes away when you open the tailgate, so the aerodynamic drag actually increases. The effect is to increase the size of the turbulent wake behind the cab and therefore increase the drag.

 

My truck is in my sig. I have 3.55LS rearend. I get around 17mpg on the highway, 11mpg in the city, and the mixed driving that I normally do comes out at around 13mpg.

These are very similar numbers to what I got on my 93 f150 4x4 with 300 I6 and 5speed manual.

I am happy.

 

See profile below for truck data:

I check ALL of my mileage, have since I bought the truck.

Truck now has 78K on it (4.6L)

22,784 miles burning 1,436 gallons of 87 octane.

Average MPG = 15.86

High = 18.38
Low = 12.33 (pulling 3500# trailer in headwind and hills)

Most driving is +/-30 mile trips at 45-60mph about 60% hwy and 40% steady flowing city/traffic.

Raw numbers over long time period = good results and REALISTIC mpg.

 

For ya'll who think that 16 or 17 mpg is bad, just look on the bright side of things. My dad's Toyota Landcruiser gets around 12 highway, and it's an I-6. So things could be worse...

 

I have a 97 F250LD 5.4lt 4X4 with the E4OD. I run Castrol 15w-40 in the summer and 10W30 come winter. You can read my mods to the truck in my signature. When I am on the freeway I was able to get 19.8 mpg in the summer(I was very surprised by that, I checked my math twice and still got that number) I run about 65mph when on the freeway . In city driving in the summer I get close to 15 mpg. The winter months it seems to stay steady 14.5mpg city or freeway.
Hope this helps, Michael

 

I've only had my 1998 f150 supercab 4.6 for a short time. I hope my gas mileage improves in the summer. I'm not really too concerned overall, but a little better would be money in the pocket right?

<http://www.fueleconomy.gov/feg/noframes/19794.shtml>

That's the car to get if you like gas mileage :P

As a disclamer, I really have no problems with my gas mileage. I really do love the vehicle that I drive

 

I have 97 SCAB 4.6L A/T 2wd that I have 80,000 miles on. I've done nothing but routine maintenance. I average 16 mpg in the city (Phoenix), and 18 mpg on trips driving 70 mph. Pulling my bassboat drops my mileage by about 2mpg.