Computer program, fuel mileage, and altitude.

[spin180]

Need some help figuring what's up with a friend's 2002 Explorer, all stock except for a drop-in K&N filter.

About 2-3 months ago he took it in to be serviced. Dealer reprogrammed the computer, an 'update' of sorts. Ever since then his fuel mileage has been worse than before the service. He was getting about 18-19 mpg with stop & go, in town type driving. Afterwards in only averages 15-17 mpg at best. This in in the mountains of NC

Last week he and I took a trip to the NC coast. The entire time down that way he managed to get around 20-22 mpg, both on the highway and in town/stop & go.

I think that the difference in altitude and the density of the air may have had some effect on the mileage. However, he was discussing the matter with some other folks and they mentioned that Ford may possibly program the engine computers differently depending on where the vehicle is going. That is, a vehicle destined for flat, low-lying areas may be programed differently than one going to a higher altitude, mountainous region.

Is that even a possibility? We're just trying to figure out if there may be something up with the programming in the computer that caused the difference in mileage; related to the change in climate/altitude.

It's a bit difficult to explain my thinking/reasoning on this and I hope I have made it clear enought to understand. Anyone have any ideas, thoughts, etc?

Thanks for the help,
Steve

 

[410Fortune]

The trucks computer can compensate for the altitude changes.
I am not sure if they still do, but back with OBD-I at least they would use different calibration codes base on where the car would be sold. CA cars always had higher emissions calibrations and Denver used high altitude calibrations.

However your dealer likely just performed some standard computer updates, which is good.
You should not be concerned about having any further work done based on the altitude of where the truck is used. The computer can compensate for that, built in.



ALOT of things effect MPG, ambient temp, humidity, tire pressure, gas octane, fan and clutch, wind, other traffic, hills, etc etc.....
it is likely the trucks computer is now more in touch with what the actual milage is. Example, my dad has a 02 F-250 with the V-10, the overhead console never moved from 14.1 MPG, then he had it serviced at the dealer and it moved!! hahaha once......to like 15 or something.