Hey guys, I have a 01 F250 CC, 7.3, 4x4 stock except for the Deablo tuner. I tuned it to the econ. setting and went from 18 to 22 Highway MPG unloaded on Summer Fuel. I rarely ever tow and put 80 highway miles on it 5 days a week. I run 2100 RPM @ 70mph due to the factory 3.73 ratio but ususally drive 75-80. I run stock tires 265/75/R16. If I slow it down to 62MPH I will get 24MPG but I cant drive that slow especially when everyone else is doing 75 or so and I would rather dirve faster to get there since I am not a fan of driving that much.

I would like to know the best way (from Experience) that I can lower the RPMs and therefore increase the MPG by at least 3-4 MPG on summer fuel.

My thought is to change out the Gear ratio to 3.08's. I am not worried about the loss of umph from the start, this is a truck, not a race car, I dont tow very much and when I do it is very light loads.

Thanks in advance,
Richard

 

Plowing air takes energy (fuel). The energy needed increases at the square of the velocity, thus it takes four times as much fuel to push the air aside at 80 mph air as it does at 40 mph. Note, this is just for pushing the air aside, and does not include the entire list of other factors.

And, there ARE a lot of other factors involved, such as the rolling resistance of the rubber on the road, and the torque curve of the engine. But the single one thing that you can do to increase fuel economy is to slow down.

The second best thing is to make your truck as aerodynamically efficient as possible. Ford's already done about as much as practical in that department, so you're sort of stuck. You could try a fiberglass bed "tonneau", which makes the bed more aerodynamic, but you'll get somewhat small returns from that. Skinnier tires may help, but not much.

I realize what you're trying to do is optimize your fuel usage for a speed of 80 mph, and you can certainly do that, but it's still not going to be anywhere near what it would be at lower speeds. The cost of installing new gears, especially it you have a 4WD, will have a payback in saved fuel costs that will likely be a long time.

We play, we pay. Wish I could be more optimistic for your outcome. Gears may help a little, but they are going to cost ya'.

Pop

 

If you are actually getting that kind of mileage, you need to leave it alone!!

 

I'd take that mileage anyday.
Joe

 

Raise your truck about 4 inches, put a set of 35 inch tires on it and your effective workable gearing will be around the 3.40s. Not good for towing and you're not going to get the milage you're looking for. If I got the milage you claim, I would be happy, man I get 18 plus at 70. If you dropped it down to 70 it will only cost you a couple minutes and save you about 2 bucks in fuel, maybe.

 

I agree. Those are outstanding numbers. If its not broken, dont fix it.

 

However, IF these numbers are from the lie-o-meter, and not calculated, you'll find they are very exagerated as a result of the computer's calculations being thrown off by your Diablo.

Most of us would kill to get the milage you think you're getting. If you get this kind of milage after doing the math manually, leave well enough alone!

Pop

 

Sir Isaac could not have said it better. For every action there is an equal and opposite reaction.

 

I would love to get that kind of mpg. I was getting roughly 18mpg(summer) then I installed shorter tires and lost at least 1.5 mpg. Winter fuel came around and now I get about 13 maybe 14 on a good day. My driving habits are also all over the place.I switched to B20 a while back but have not had enough cash to fill the tank so I am not sure if mpg increased. In conclusion if you are getting 20mpg+ you should bend over and kiss your trucks tail gate.
Mick

 

kiss your trucks.......

 

Using Lie-o-Meter, I'll check manually and get back in a week or so

Thanks


Tired of a slow internet connection? Just press Alt+F4+Enter and it is amazing how fast it gets!

 

24 MPG in a PSD. I get 10-11 MPG and drive at 2300 RPMs. I must have a different truck. I am confused.

 

Must be driving Toyota or Honda.

 

I also can only dream of that sort of mileage. I get 13 empty and 8-9 towing.

 

Don't be too heart broken when you see the real numbers. You may be in for a REAL shock.
Joe