If you get the Super Chips Advantage Programmer with the Data logger and have a know how on a/f and load, spark timing you can get superior results. I have the 97 4.6L auto everything is stock and after fine tuning this truck over the past few months the mpg on the hwy is 23mpg @ 65 mph and in the city it's 17. One of the biggest problems with trucks is that they are programmed to haul loads and the a/f is fat along with the timing set to no more than 23-25 degrees advance....Ford done it that way so you can't really toast the engine and the trucks will work well in many types of environments and your oil gets dirtier faster due to excessive fuel. The programmer even lets you change trans shift points as well as firmness....also 2nd and 3rd are locked and that also helps in the mpg department. drive with an easy foot 2000 rpm during traffic and the guy that's in a hurry will be waiting at the light for ya.
If anyone has the advantage from SCT. Let me know and we can compare notes.

 

I'm only getting 12.5 MPG at best!! Have put 285's on, have a soft tonneau cover and can have a heavy foot at times but i do practice driving style suchs as coasting to a stop in nuetral and not heavy-footing it in the city. I am very aware of fuel consumption and try to take it easy, but I'm sure you all know, sometimes you need to be a bit more agressive on the road then desired. I am runining 95 octance, i have installed a DiabloSport Predator and advanced the timing all the way. I seem to recall better fuel mileage before installing the Predator and hoping for anyones thoughts on the matter. Although fuel is still cheaper here then it currently is for you guys back home, 400 KM's to a tank i think is a bit ridiculous.

 

Need to bring this thread back to life.

Still suffering with poor mileage. Any thoughts on how much effect the air conditioning and 285 size tires would have on my mileage?

Here in the sandbox we have to have the a/c on 100% of the time. Cooler months are approaching so I will be able to ease off on the a/c usage. Would that have the effect of losing mileage as I mentioned in my previous post??

What about the tires? Just had an alignement so that should be fine. Did crank the torsion bars but I think that will have a negligable effect on mileage.

 

A/C on will add 5%-7% load that the ECU sees and calc's the engine accordinly. Taller tires increase the load to accellerate so in the ecu load tables the taller tires lower the rpm and increase the load= more fuel or TQ to move along..almost like haulong a heavier load.