Posted this in the wrong spot yesterday, so I thought I'd try again here to get some more opinions. Last week I installed new plugs set at .040 and now it seems the avg mpg (per the overhead console) has dropped from 14-15 to 11-12 mpg. Plugs were the same, Champion RC12MCC4 copper core, and other than the gap of some of the old ones being up to .050, the old ones looked okay. The truck is a 4.7L 2002 Durango, 115K miles, Airaid intake w/TBS, and 31" AT tires. I've owned the vehicle for 30K, and this is the first plug change that I have done. I live in PHX, and although its 105+ I haven't seen a drop like this for the last 3 years. Can I trust the overhead, or should I manually divide the miles into the tank to know how I'm doing? Reseting gives me the same results. Payed close attention to the avg this morning to work = 16 mpg. On the way home with A/C = 14.7. Have to say I constantly was looking at the gage trying to go easy and get the most mpg. Not the way one would drive. If I just drive the speed limit, avg goes down to the 11-12 range. Shop guy tells me its just the engine going through gas to keep me cool. Curious to hear what you all think.

 

the A/C does suck up alot of gas (i go from 18 highway w/o it to 16 w/ A/C on)

however i dont trust the overhead console, it is sooooooo inconsistent i could drive the same route every day two weeks in a row, the first week it says 19, the next it will say 15 no understandable reason for it, so i just hand calc everytime i fill up and i suggest that you do the same

 

If you're getting those kind of numbers I guess that makes me feel a little better.

 

just try to reset the computer

 

+1 on that! https://dodgeforum.com/forum/1st-gen...ine-light.html

 

Thanks for the info on computer reset - I'll keep that in mind. Will do some manual "studys" on mpg to see what's reality. Oddly, the mpg per the console seem to be about 15-16 now when it was like 12 when I changed the plugs. Maybe I was on the gas too much w/the A/C on. Thanks all for the help.

 

Ya, never rely on the over head cause their never right.

 

thats not true, there was that one time . . .


(yes only once has my overhead agreed with my actual mpg )

 

Don't tell me your gunna start talking about your flute you used that one time in band camp!.....

 

band camp??? whats that???