Gas Mileage Friggin Problem!

[RickE46M3]

Alright I have a 1999 XLT 4wd. I typically can get 300-315 out of my 20 gallon tank, and that is not with conservative driving. I just got my shocks done, new springs and leaf supports as well, no alignment yet and now I am seemingly getting robbed of mileage per tank... I am at half when I've gone about 115 miles... overall I get 250-260 out of a tank now... that's like 14 miles per gallon if I round UP! Out of a 4.0 and my driving has not changed... I need help with a diagnostic. Thanks

 

[sparky2263]

Certainly sounds like an alignment issue.

Also, changing the rake/height of the vehicle can impact aerodynamic loads if most of your driving is highway driving.

 

[96limitedX]

have you taken in to account winter mix gas? most if not all northern states changes there mix for winter. i'm currenty getting about 12mpg in town..summer time i get 15. its just what happends in winter(atleast here due to running in 4x4 all the time and winter gas)

so thats somthing to think about.

 

[Mbrooks420]

Do you warm the truck up more in the winter?

 

[RickE46M3]

Well I live in Maine, maybe that's the difference. Some say the alignment would'nt affect crap. I'm not engaged in 4wd hardly ever, maybe twice this year so far we have just had not much snow and even when we do I'm in Auto because its more fun lol... this is just killing me that I'm getting a whopping 14mpg out of a ****** 4.0

 

[sparky2263]

Some say the alignment would'nt affect crap.

That's insane. Rolling resistance has a large impact on fuel mileage.

 

[Creager]

Whats your temperature gauge reading at?

Having improper coolant/water mix, having air in the system, having a worn thermostat, or it being simply too cold outside (<20 degrees) will cause the motor run cold. Which in turn, the EFI has to run rich to make up for running cold... which would explain your loss in fuel mileage.

A small trick is to run a piece of cardboard in front (of one half) of the radiator. This will allow the radiator and cooling fan to still do their job, but not to over-do it when you really don’t need it (in the winter months).

 

[rscalzo]

Gas Mileage

As soon as the winter mix gas started being pumped, I dropped from approx. 19.8 mpg to 17.5 mph.

 

[RickE46M3]

What is in the mix? I didn't think it was even an issue I bought my truck last year in March, I was in winter and I didn't see it this bad...

 

[rscalzo]

Gas Mix

During the winter they add a chemical that cuts down the emmissions but reduces the mileage. I'm not sure of the chemical but they have been doing it in the colder states for years from northern NJ up to Maine.

 

[Mommystrucky]

dude dont feel bad...i have a 96 xlt 4.0 and i only go about 240-260 on a tank...thats like 12-13 mpg!!! worse than my 99 f-150 xlt

 

[celly]

Winter gas definitely brings my mileage down. Fact of life in Canada I guess.

You want crappy mileage? Get the AWD V8 combo. I was getting pretty decent mileage in my SOHC V6 but it's dropped a fair bit. I do prefer to V8 though. Plenty of low end and it sounds cool too.

 

[96limitedX]

celly, our V8 AWD combo gets a steady 14mpg(exactly whats on the window sticker) all the time(in town..highway its about 20mpg). has never dipped below that. its better then what my ohv V6 gets in town.