Tuners mpg improvement

[rowekmr]

I have been reading on tuners imprroving mpg's after finding a 00 F250 CC 4x4 where the owner claims to get 23-24 mpg's on highway and wanted to know is that a real benefit or is it the result of the tuner recalibrating the computer and the readout is a reflection of that not a real improvement. I'm asking because I remember hearing about tuners doing this to the readout of the gassers awhile back.

[jgorm]

I can't comment on these trucks, but I know there is a parameter that can be altered to change the mpg display on the dash on some vehicles.

[Justin@DP-Tuner]

A true 23-24 MPG is about impossible. You can't go by the lie-o-meter. The only way to know true MPG is to hand calculate.

[brotherxb]

You would have to about render the truck useless as a tow vehicle to get that kind of mileage.

[INFRNL]

Originally Posted by brotherxb

You would have to about render the truck useless as a tow vehicle to get that kind of mileage.

and get rid of the front 4x4 axle
and possible take out the skinny pedal
and possible lose the keys

If you had a 2 wheel drive manual standard cab with stock tires/3:73 gears and drove easy; you could probably hit 20 or so on the highway.

I have hit 18 in my huge automatic dually. There are always so many mpg #'s thrown around on various forums; not sure what to believe. I have never personally seen anything better than what I get, but I know you should easily be able to hit 20mpg in a smaller truck, single rear wheel, or manual.

I also have not seen any improvements ever using DP or TS on my current truck or my old 99.5. However I have not lost any mileage either, but have a ton more power. My 99.5 got 14-16 in the city racing around like a teenager using canned ts chip/tunes

[SmokeyWren]

A big factor in MPG for '99-up 7.3L PowerStroke pickups is luck of the draw. Some can get up to 20 MPG cruising at 65 MPH on the flats with no load in/on the truck. But most will get about 16 to 17. And my unlucky draw meant mine got only 15 to 16. I tried every trick in the book to improve MPG, but the only thing that worked was to slow down and put a raw egg on the go pedal. I had tunes from three different well-known tuners, including economy, towing and 120 HP performance tunes, and none of the tunes improved my MPG.

Almost always, when some guy spouts off about better than 20 MPG, you can bet he's either relying on the lie-O-meter in a Lariat, or he doesn't know how to accurately manually calculate MPG.

To do it right, you must fill the tank to the cap with liquid diesel - not foam - both before and after you make your mileage run. That requires about 10 minutes after the automatic pump first shuts off - and with some pumps such as Flying J you'll probably give up before you get the tank full. And you must have a calibrated tripmeter with less than 1% error.

To see your tripmeter error, drive 100 miles on an interstate highway without crossing a state line or changing highway numbers. Reset the tripmeter to zero with your front bumper on a mile marker that's not near an entry, exit, overpass, or anything that could cause the highway crew to not place the mile marker where it belongs. Drive 100 miles per the interstate mile markers, reading the tripmeter when your front bumper passes the 100th mile marker. If your tripmeter doesn't read between 99.5 and 100.5 miles, then you need to change the tire revolutions per mile parameter in the ABS module, using a scan tool that can access the ABS module.

How much to change the revs/mile parameter? By the same percentage as your tripmeter error. Common error with stock-size tires is about 2.5%. For mine I was running stock-size Michelin XPS tires, and with my revs/mile parameter changed to 650 my tripmeter was 99.7% accurate. That's close enough for Government work. But most people don't have LT235/85R16 tires, so their required revs/mile parameter to have an accurate tripmeter will be a lot different than 655.