So your saying a truck with 600hp is going to work harder pulling 7,000 lbs than a truck with 100hp! If that's the case then you must always drive down hill not up! I drive the same hilly route pulling my drag car and after I added hp and torque to my truck it doesn't down shift as often and it gets up to speed faster without putting the pedal to the floor.

 

Horsepower is the standard measure of work used for vehicles.

Pardon the physics definition of work & consideration of the entire vehicle. 600hp will work much harder, accomplishing 6 times the work of 100hp. 600hp places far more stress & strain on drivetrain components. IMO "a truck" is not a motor by itself. I'd certainly hope "600hp is going to work harder" for you! If it didn't, what would be the point?

Your example "gets up to speed faster without putting the pedal to the floor" is a demonstration of 600hp working harder than 100hp possibly could, just as surely as 6 horses can work harder than 1. Its harder work to accelerate faster.

 

IMO horsepower should have nothing to do with gas mileage. How that horsepower is produced is the important part of the equation.

The very definition of "work" should prove that, at cruse, the 600hp engine is producing the same amount of horsepower as the 100hp engine is. It only takes a certain amount of power to keep the vehicle steady and if you are producing any more than needed, than by definition your vehicle is accelerating.

However, the smaller less powerful engine has a higher volumetric efficiency (due to the more open throttle) and therefore a higher dynamic compression. This is usually why the smaller engine gets better mileage (all else being equal).

This isn't always the case, though. There are numberous examples of bigger more powerful engines getting better mileage than their smaller cousin. This is due to the difference in thermal efficiency governed by cylinder head chamber design, compression ratio, camshaft profiles (determining your torque band), quality of inlet charge, and many other factors that can't be covered with a blanket statement.

 

IMO its a worthy goal to increase MPG with any horsepower, any engine, any load & any driving style, on a vehicle by vehicle basis. Blanket statements will always be undermined by exceptions & variables. Mostly vehicles spend their lives with the drivetrains they were built with. It is 'off the shelf' modifications to OEM that was the original subject of this thread-not the inifinite range of hypothetical alternatives. Theoretical mods are often impractical, especially for the individual & mostly outside this equation.

Achieving better MPG for any given horsepower is the Holy Graille. In this way horsepower and gas mileage are intimately linked.

GE ran ads about their energy efficient locomotives that accomplish doing 'More with Less'!

 

Very true that is the exact reason I traded my 1998 Ranger supercab 4x4 off road 4 dr with the 3.0v6 auto trans and 4:10 gears I only got around 17 mpg on the same exact trips! My dad had a 2001 F150 Supercrew 4x4 offroad 5.4 auto with 4:10 gears even the same 265 tires and he was getting 17mpg aslo! That was my reasoning for upgrading to the F150 in the first place! I used to tow my mustang drag car on a 16' car trailer with my ranger and I only got about 9-10 mpg while towing! The F150 still gets 14 mpg pulling the exact trailer and car!

 

That's the exact same reason I just got my F150 after totaling out my '98 Ranger. I wanted 4wd; all of the 4wd Rangers were also V6's that didn't get any better mileage than the F150's. At that point, the Ranger has absolutely no advantage over the F150.

Though I'll admit that the Ranger that I had with the 2.5L and 5-speed got a lot better than any F150, around 30mpg highway and in town.

 

Just a quick update I installed my e-fans and I did get 1.5 mpg increase on my first tank I had 370 miles on 19 gallons of gas! But it has been below 0 all week today it hit -26 with a 20 mph wind -46 wind chill! I hope I will see more gains this summer when it is at least +65 degree's lol!!

 

I just put Efans on my '01 F150 Supercrew 2WD w/4.6L about 4 months ago. I live in west Texas where most of the driving is almost flat. It's a daily driver about half city/half highway to and from work 17 miles oneway and I drive the speed limit. My average mileage has gone from 14 to 17 with the Efans. I did the mod myself with two Haden fans and a Haden controller from O'Reilly's (about $200). I couldn't be happier. Course the previous threads are right about cost recovery. BTW if you go this route get the adjustable controller with the screw in sensor. There is an unused port with a plug in it right at the fromt of the intake where you can install the sensor with a bushing.

 

Not 26 mpg, but i am very aware of a 93, 1500 w/350 75k miles, 2 wheel drive with fiberglass cap, that will consistently pull 22-25 mpg on the highway and 19-20 non highway driving. When i drove it to the U.P. of MI, i was able to pull 22 mpg and that was running between 70 and 75 mph. This truck belongs to my Grandfather, its completely stock, I have only fully tuned this truck once, i think around 03 or 02. plugs wires cap and rotor, F.F. . It has a towing package, and didnt come with ultra highway gears.

25 mpg is possible in a truck, just not my 98 150 4x4 w/ 285/16 tires. I will gaurantee this, you will not be able to use or work that chebby near as hard as a ford without it falling apart. Fords seem to be built heavier and with that comes a penalty in fuel mileage.

 

Well I just got the Edge Evolution programmer and all I can say is WOW major difference in power! I don't know about better mpg yet I will have to test it out on the next tank full! I have been testing out the performance gains on this tank! I like the trans improvment but I really like the power of the towing tune with 87 octane!
My truck has the limited slip rear end and before the tune I could only get a chirp from the rear wheels in a straight line after I set it to the towing tune WOW! I left some very nice black marks about 20 feet long and I gained 19hp and my 1/4 mile time was 16.13 at 84 mph! I just tried the all out performance tune and I gained 24hp and my 1/4 mile 15.95 at 86.4mph! I am very pleased with the Edge Evo my dad has the Hypertech programmer III and it is close as far as gains but he can't leave as long of balck marks as mine! Our trucks are basicly the same exact truck both are 2001 supercrew 4x4 with the 5.4 the only difference is mine is a Lariat with 7700lb GVWR package and all the bells and whistles his is a xlt!

 

I have gotten 25 mpg with mine....lol But that is an Imperial gallon. I have always thought these things could get better mileage, but like the others say there is no return on investment. Mine gets about 20 mpg US gal on the highway. In town it sucks and in winter it's even worse. Driving habits do help somewhat.