Hey guys i know this has been asked before but i couldnt find any answers for a 5.7, i have a 2003 quad cab 4x4 wit 63K miles. and recently my total mileage per tank has drop almost 60 miles. i just cleaned the throttle body 3 weeks ago and cleaned the filter. Has anyone else had this happen or have any suggestions to what i could do....thanks in advanced for your help.

 

Do maintenance your manual says plugs trans oil diff etc

 

did you get gas that had lots of ethanol in it? 10% can make a big difference
Maybe you just did lot of local driving or where do you live? it's been cold around here and using a remote starter or starting your truck up to get it warm will knock off that kind of mileage.
In the winter my car gets on average 25mpg with me starting it an warming it up every morning. During the summer I would get 31mpg on average. That's a loss of about 66miles per tank

 

I plan on doing the plugs soon, just still trying to figure out which ones im going to go with. Could the fluid in the front and rear diff's really make that much of difference?


As far as the ethanol, its a Hess station which they have the best prices in town so that could be a reason for the drop in their price and my mileage....and ironically yes i do have remote start and us it every morning. i didnt think that it would effect it that much though....

thank you both for your input

 

The remote starter effects more than you think! Try not using it for an entire tank and see how many more miles you gain! I was shocked at how much the difference was in my car.

 

my mpg has gone down to about 14. winter gas gives you less mpg cause of all the stuff they put into it. and warming it up in the mornings really affects it quite abit. also my superchips gives me a good 2+mpg. also driving in 4wd through the snow will drop it too.

 

Idling = 1 gallon per hour (rule of thumb...I'm sure a big V8 is probably pretty close to that) 10 minutes every morning and 10 minutes every evening at work means a gallon every 3 days; defenitely would contribute. Also, some states still allow lower quality gas in the winter that decreases fuel mileage.

 

my mileage has also dropped off alittle. 13.8 down to 13.3. not enough to make much of a difference but i also warm my truck up in the morning and am thinking that the winter blend gas also helped it drop.

 

you guiys are getting 13!!! i get about 11.6 mpg and thats is with babying it and on highway the best i get is about 14 doing 80-85mph...is anyone else getting this bad of gas mileage

 

It depends on your gears too, if you've got 3.53s you'll get better mileage than someone with the same truck but has 3.92s, or 4.10s, or 4.56s. I've got 33" tires and 3.92 gears and at 70mph I get 16mpg. I'm sure if I was doing 80 I'd get 14mpg too. Around town I average 12-13mpg.