wierd mpg

[1991LRrrc]

so i got a question for you all. my wife and i went to salt lake we have filled up in heber and long story short we went 217 miles and only use 12 gallons then today we started heading back to duchesne we filled up in west valley utah and headed back home stopped in heber to use the bathroom and get something to eat and i top of with gas nether to say it only took 2 gallons and from west vally to heber its 48 miles. so how can this be? i got the v8 all stock other then the lift kit and 245/75R16 a/ts. didnt do the injector cleaner have done a complete tune up but thats been months ago. I'm not complaining about just shocked that it got this good of gas mileage and its puzzling me on it too

 

[aliastel]

Wind direction? I've had some pretty great mpg figures with a good tailwind.

 

[p m]

On I-70 between Green River and Salina, my D1 would show anything between 10 and 19mpg, depending on the wind.

 

[76FJ55]

Take a look at your fuel tank and make sure it isn't imploding from a clogged vent line not letting air in as the fuel is drawn out.

 

[1991LRrrc]

fuel tank has the air that gets into it. where on one of the vents on the tank its self is broken so it leaks if i put to much gas in it

 

[discostew]

Take a look at your fuel tank and make sure it isn't imploding from a clogged vent line not letting air in as the fuel is drawn out.

They don't usually run very well when that's happening .

 

[Blueboy]

I'm starting to run into that problem as we cross Alp passes from lower elevation.

Make a habit now of stopping along the way and opening the fuel cap to equalize the pressure.

Really affects the idle.