Gas mileage in '02 4.0 V6

[kylecolb]

So it seems my gas mileage has gone down some lately. I am getting around 12.6 mpg in a 2002 XLT 4.0 V6, all city driving. I haven't done anything lately besides put in a performance K&N air filter. I used to get around 13.5-14.5mpg. What things can I do to boost my gas mileage? Thanks.

This summer I got about 20-22 highway when I went on vacation. All highway driving then.

And I have around 96k miles on it. Should I switch to Synthetic oil in the truck, and if so, then how often should I get oil changes?

Thanks

 

[waskly]

winter gas

 

[lynchy wa]

caldwell had this drama,fuel pump sensor fouled i think and like waskly said winter fuel additives to blame maybe something to check.
go synthetic and change every 5k - mine runs 5w which is bloody thin but recommended down here.

my fuel economy went from 14.2l/100ks to 15.1l/100ks (sorry about the metric ive lost my conversion chart) after the airbox mod, more air in = more power = more fuel used? dont know but i hope the magnaflow will bring me back down to around 14l/100k

ok found conversion 16.5 mpg down to 15.5mpg

 

[kylecolb]

I never finished the air bix nod though, only have the air filter in so far... will fuel objectors cleaners or any gas additives like those help?

 

[lynchy wa]

sorry mate i'd only be guessing maybe plugs or fuel filter could be checked caldwell said that fuel sensor thing happened on his 03 as well definitley worth looking into but i hope someone who KNOWS what their talking about jumps in.

 

[Ronin8002]

I never finished the air bix nod though, only have the air filter in so far... will fuel objectors cleaners or any gas additives like those help?

Fuel injector cleaners/additives don't really help with winter blend. You might give them a shot since you have 96k miles but I wouldn't expect a miracle.

Best mods you can do for mileage are:

-Underdrive crank pulley
-Electric fan
-Airbox mods
-High flow muffler
-Maintain 40 psi on your tires
-Synthetic oil
-Synthetic transmission/differential fluid

Avoid short trips in the city if you can. Stop start driving really makes for bad mileage. Our trucks tend to do well mileage wise on the highway though. I think this is partially due to most people having 3.55 gears. These trucks could probably benefit from a 4.10 gear swap