PowerStroker77,
In regards to your tailgate question. I read an article, where I don't remember of course, that driving with the tailgate down creates a drag. The flow of air goes over the hood, cab, and then down into the bed. With the tailgate in the up position you create a "bubble" so to speak. Kind of like a bed cover or camper shell. If you take an empty bag of chips and put it in your bed with the gate up while driving you will see what I mean. It will float around your back window before it actually blows out. Does this make sense? I hope I am explaining it well.
I have not tried to check on gas mileage but I can say that I took my old Dodge Ram ('97) to the drag strip and my slower times were with the gate down.
I hope this helps. It is only what I read. Don't know the fully scientific or correct answer. If there is one.

Chris

 

PowerStroker77, I have a 2000 F-250 PSD 4X4 with 3.73 gears. I'm pushing approximately 1900 - 2000 rpm at 66/67 mph. I'm averaging about 18.2 mpg. 80% freeway/20% city driving. I usually set my cruise control just above 65. That's why the 66/67.
No mods, but thinking about the micro-tuner.

2000 F-250/SC/XLT/4X4/PSD/6Spd/Longbed

 

Thanks for the info guys!

 

Two things.

1. A boost guage is an excellent tool for getting better fuel mileage. You could almost make a MPG guage out of it if you were to re-letter it from say 12 MPG at the right side up to 25 MPG at the left side. Rear end ratio, aerodynamic profile will all affect boost requirement, as the turbo will naturaly spool-up in response to increased load.

2. Regarding tailgates. I've participated at the Bonneville salt flats for a number of years and I've noticed that the hot set-up for trucks is #1 a tonneau cover, or #2 no tailgate at all. A net, I think, would be the worst possible senario. Did you ever see any of these military drag parachutes? They look an awful lot like nets to me.

BobJonesSpecial

 

Bob-- would the boost gauge do anything for my non-turbo 7.3 IDI diesel? Or does it only apply to the turbo rigs?

 

I have a 02 SC4x4. I get a hair over 21 running 80 on the highway empty. I just put in the superchip tuner, at the 90HP setting and it went up to 24.5 highway.

 

thinksnow= how did you figure that one out, by the above console or the old fashion way==fuel up couple of time and divide mileage by gals of diesel.

 

The old fashion way. I wait until I have below half a tank then fill up and divide. The computer tends to be a bit optimistic at times, other times its way below.

 

The K&N will give your engine "cancer"! It allows too much past the filter and causes engine damage over time. Cummins even goes so far as to specifically single out K&N and state that these filters should not be used. Surely if it damages the Cummins it will damage a PSD.

 

25 MPG is probably due to using PUs computer (not manually keeping track and dividing), overstating, or a combo of both. Maybe if he lives in the flats and drives very slowly?
1995 stock, drive at around 2000 to 2200 RPMs (65 to 70mph), use diesel from major truck stop, mostly interstate to OKC and back, I get from 17.1 to 18.4 MPG. The fluctuation is caused by how many trips of stop and go driving in town, oil change duration, and whether I have in cetane/injection supplement.

 

that still seem to be the right way to do it, i;m going to tried that way using half of tanks , I also got duel tanks in my truck.

what type truck you have, what gear ratio also, what type driving you do also, any elevation driving.

 

I have a 97 250HD PSD 4x4 king cab with an 8' box I am unsure of the gearing but it is a stock truck, execpt the K&N air filter and coolent filter. I get, on average, 18mpg, with a full saddle tool box and some junk in the back seat. The best I have ever gotten was 21 mpg on a trip to NH. I like to keep all the reciepts for my fuel for the month and I jot down the mileage, beginning and end, then I divide. It seems to be a more acrurate number that way.

 

There is really only ...ONE...way to calculate consistently Correct fuel milage figures. You have to fill your tank to the SAME level or volume each time you fillup. For instance, I always fill my tank completely full. I can add 4 gallons of diesel after the filler handle shuts off, which most would call topping off the tank. I get around 17.xx something and i'll hit 18.xx on a long trip if I keep my speed below 2,000 rpm's. .....s.kuteman

 

Yes, it is possible to get really great mileage with a powerstroke. I have a '94 f250 and usually get around 21 to 22, but have gotten as high as 26.9 mpg (with the tailgate down). This was on an 800 mile trip over interstates about 70 mph (I figured my mileage the old fashioned way since I don't have a trip computer in my truck).

 

You also probably have a 3.55 axle ratio though right? I think the vast majority of us have 3.73's, which top out around 20 mpg.