getting bad gas mileage on 4.0L
 

just figured out that I just got 12.41 miles to the gallon on my last fill up. granted i've only driven around town and once or twice gotten on the highway and went 90 for 5 or 10 mins, also i got a flashpaq w/ the performance tune.... but I never got that bad mpg's before. for a while I was getting real bad mileage but I didn't know that the compresssor comes on when you put the heat on panel/floor setting so I stopped using that setting. is there something else wrong? I just changed the plugs 6 months ago and had the exhaust repaired and everything was all good, and I'm about to replace the battery on it cause It's on it's way out but the battery should have nothing to do w/ this problem. truck sounds and runs good. anybody got anything for me?

dude thats normal...i get 12.5-13.5 city...its a truck not a car

yeah but i was getting better than that before, 12.5 mpg seems horrible, it's a v-6

yea with the MPG of a V8 lol...get used to it...the always locked front hubs kill MPG and the fact that its auto doesnt help...drive with a lighter foot

i baby the thing, i never get on it, it just seems like the mpgs's just dissipated all the sudden

another thing you have to take into consideration is the tune...it changes the shift points to higher RPMs...thats using more gas

Maybe someone got into your tank while you was parked. With the price of fuel keep going up we all may see more of that.

dude my 3L gets that mileage lol..

do you use the parking break at all? mine froze up on me for a while and caused me to drop to 12.5-13 mpg but i normally get around 15 no matter what im driving be it highway or city.

That's normal... also, if you go TOO fast, it decreases your fuel economy.


Get a Geo Metro if you want great gas mileage. lol

Thats worse than normal. I have cranked T-bars and larger tires, and even with a heavy foot I get about 16-17. And yes, that is corrected for the larger tires. Going above about 75 on the highway will crush your mileage, but you didn't do it for that long. I get about 13 when towing a 5000lb trailer.

wintertime i get 16mpg with 33's and a 4" lift. summer is well over 20 mpg. guys, get your trucks looked at. both numbers are city btw.

Its not a truck, its a Ford Ranger. The MPG a 4.0 gets with 4wd is pretty sad. Full size trucks do just as well, and you actually have something that has room, can pull something half way decent, and doesn't ride like a lumberwagon.

Have you changed the wires with the plugs? What about 02 sensors? Cleaned the MAF and TB? Maybe try Seafoaming the engine?

how do you actually know how much gas your consuming? the first time i did my averages i averaged about 11 mpg city.

i then realized that my gauge reads at empty when i have almost a quarter tank left. everytime you fill up, at the click stop putting gas in. then the next time you go and fill up, however much you put in is how much you consumed. you can't trust your gauge. after i figured that out it turns out i get like ~20mpg which isn't too shabby with oversized tires

Switch to economy tune, there isnt much of a diffrence but with mixed driving I get 18-20mpgs

yeah but it doesn't matter how many miles you drive or how much you get out of the tank, its the miles driven divided by how many gallons you just filled up with aka what you just used for those miles driven

yeah i tried that before and I didn't notice much difference, i switched back tho. for some reason before I couldn't figure out how to turn the speed limiter off on economy but did, and that was one of the reasons why i went back to performance tune. truck still hauls even in economy. i'll see what i get this time around for mileage

Change your oil, new plugs, new wires, new upstream o2's and clean your MAF. All of that might get you to 15mpg.

And new air filter and fuel filter cant hurt either.

oil is changed every 3k w/ a blend, just did the plugs &wires. what are upstream o2's? also i've been told it's not good to clean the maf sensors because they have some sort of coating on them, but i've used maf sensor cleaner to clean the Idle air control valve and things got better

The coating can be effected by harsh cleaners like brake or carb cleaner. MAF cleaner is made for that reason.

The upstream O2's are made of the same metal as spark plugs so when the plugs are worn out they are too. The computer will check the up stream o2's to make sure the maf is ri9ght and can adjust the fuel curve.

The IAC is really POS design, I find that harsh chemicals work best on it. Followed by a silicone spray to keep it lubed. Otherwise replace them when they howl in the heat of summer.


FWIW, beating my truck gets better mileage. The faster I can get into OD the better the mileage I get.

I just got back from Boston this afternoon-350 mile round-trip, 21.2 MPG!!!!
I will NEVER complain about that.
MikeR

Just for a reference to anybody - I get 18MPG with my 5.3 V8 on my Chevrolet Silverado 1500 (1999) 4x4.

12MPG seems rather low for a 1/4 ton truck with the 4.0 v6.

The 4.0 was born in the 60's as a 1.8 in crappy British sports cars, that LS based 5.3 was made to be efficient and powerful. Total contrast in tech, ford should have killed this engine in the 80's. Its durability has kept it alive long past its prime.

Old Chevy 350's and Ford 302's can get the same MPG in a fullsize 4wd pickup, and that technology is just as old.

ditch that programmer!! i got my new ranger threw my super-chips at it and couldn't figure out why i was pulling 14MPG max.. was horrible. so i did a test today coming back from T.O. went back to stock. easily gained 30% economy on a stock tune. was astonished. did same trip, same speed, same everything one way with the tuner one way without. proof is in the mileage. Before i could get like 100km max / quarter tank. today i pulled 165 - 175km / quarter tank. unreal difference. and i always ran the economy tune... food for thought. i know i didn't want to believe it either.

Definitely not "normal"

My mom's 99 explorer (which I routinely drive to school which is about a 60 mile round trip) get is 17 in the city and 21 on the highway. It is a 4wd automatic.

Ditch the programmer, drive slower, keep it waxed, clean and tuned up and the SOHC will give you better mileage than the OP is seeing now. Accelerate slow...that this best "trick". Keep cruising RPMs right around 2200-2500 RPM's and try to shift (if it is manual) or hold the RPM's right above that (if it is an automatic)....that is where the motor makes peak torque. Anything higher than that and you are just spinning the motor faster to accomplish the same amount of work in a shorter amount of time with the trade off being more consumption of fuel.