Increase mpg?

[Thermo]

enthusiast, I have pushed my expy to the limits with a short lift and have no problems diving into about any part of the truck. So, I have learned a lot and have a lot of diagrams that if I haven't dove into that part of the truck, can atleast give some helpful information.

If you have a question, feel free to PM me and we can discuss it away from the forums. I will try to give you my justification for why I may say what I do so you can make the final decision based on facts other than what I say. You will find that with my background, I have a fairly unique perspective on things as I play in both the electronic and mechanical side of life for my job and therefore can look at things from all angles.

 

[SWAGGA]

Hate to say this, (prolly raise some flack) but Ford has huge teams that do NOTHING but optimize their products for mileage.

I have to disagree... ford EFI vehicles (n/a) tend to be quite detuned: they run rich and don't have enough timing . There's more to it and different ways to achieve it by vehicle, but in all honesty, most of EFI tuning is a/f ratio and timing. When optimizing those, you get more power throughout the curve and fuel mileage improves. When you have a vehicle that averages 15mpg highway, and you bump 2mpg safely with mild tuning, that says a lot.

I'm not going to read the entire thread so this may be completely a repost, but a few general principles for all vehicles particularly trucks / SUVs:

-Driving style, this is most important.
-Tuning as mentioned before.
-Tire pressure--this is huge, it'll kill your mpg if it isn't high. I typically run mine slightly higher than recommendation (no more than 5psi, personal preference.)
-Synthetic fluids. (Engine, transmission, differentials.)
-Intake/exhaust... but be careful choosing and consider the bang for buck.

 

[1997SCEBFEX]

Perhaps I missed it, but is this computer mpg, or averaged out after fillup each time.
I've averaged ~13.5mpg over its lifespan since purchase...some as bad as 8 mpg while towing, and some 17 mpg for pure highway.

 

[Thermo]

SCEBFEX, for me, it is based on calculated mileage from each fill up.

 

[1997SCEBFEX]

SCEBFEX, for me, it is based on calculated mileage from each fill up.

Same here Thermo.

 

[toms89]

SCEBFEX, for me, it is based on calculated mileage from each fill up.

Same here.. Dont have the computer display that tells you your milage.

Current mileage minus previous mileage reading divided by gallons to fill.

Of course it all depends on how much you top it off but it all averages out over several tanks.

 

[fordenthusiast]

according to the photos of the blown 2000, it looks like a tight fit in there !!

 

[MUSKYMAN52]

I have the 5.4L with that annoying controltrac. I get 11mpg to a gallon consistently. As of yesterday i installed my new thrush glasspack and today i removed my resonator. When i run through a full tank of gas ill let you know how much i gained or lost cuz i like the rumble haha. I can feel the gain of sound, she roars now.

 

[MUSKYMAN52]

Put on a glasspack and did a resonator delete and even after 20 minute defrost everyday, i went from 10mpg to 12.5mpg pretty dang happy

 

[toms89]

Put on a glasspack and did a resonator delete and even after 20 minute defrost everyday, i went from 10mpg to 12.5mpg pretty dang happy

What year expy? My 2000 did not have resonator. Just muffler and 4 cats.

 

[FordandPolaris]

What year expy? My 2000 did not have resonator. Just muffler and 4 cats.

I may be wrong, but after 98 didn't they add in a small resonator towards the end of the system? I always wondered what that little canister looking thing right before the end of the tailpipe was. 97 and 98's do not have one.

 

[toms89]

I may be wrong, but after 98 didn't they add in a small resonator towards the end of the system? I always wondered what that little canister looking thing right before the end of the tailpipe was. 97 and 98's do not have one.

I have a 2000 and certainly do not remember seeing one. No longer have stock exhaust though.

Edit: Just checked service manual. Looks as I remember no resonator. Maybe a different model year? 2nd gen??

 

[toms89]

OK ...... my 2 cents..and sure some if not all has been said.

The Gotts mod (or ANY CAI for that matter) is also a very dubious mod if mileage is your goal. The restriction for any mileage consideration is in the throttle body, as it will only be open to about 25% or so during cruise. Having a "better intake" means very little when your pumping losses are right there at the throttle. (One more reason why diesels can be more efficient)

.

I have to agree with the above assessment as far as intake mods ahead of the throttle body. Gotts mod may potentially increase w.o.t. hp but would do very little for fuel economy if your throttle plate is limiting airflow.

As far as tuners there is some to be gained there. Only because ford has to compromise between reliability, power, fuel efficiency and emissions. I don't believe any "tuner" is better than or has more resources than Ford but that they simply have different standards they are required to meet. I can tell you most of the power and efficiency to be gained is from further advancing the ignition timing. In the past you could simply do this by adjusting your distributor now you have to get a "tune".

Decreasing parasitic drag is always good for economy and electric fans are one of the easiest most reliable ways. I personally am sticking with stock fan for reliability and pure volume capacity should the need arise. Partly based on my own experience with an electric fan on my highly modded mustang.

If you keep the tires pumped up near max it would help reduce rolling resistance at the expense of ride and tire wear. Whether it saves in the long run due to early replacement of tires would be interesting to find out. I like to keep mine just a little above the vehicle recommended pressure.

Driving style can have a lot to do with fuel economy. I would suggest finding your expys "sweet spot" where you get the maximum output with the least amount of throttle input. This can be found by "feel" monitoring your right foot and it has to be done with economy in mind.

Unfortunately you are fighting mass and poor aerodynamics with an Expedition. Increased parasitic drag on 4x4's.

 

[mbaessler]

Great data Thermo! Thank You
Mike