Crap fuel mileage

[Maverick]

For some reason my fuel mileage has gone down. Last few fill ups I've been averaging 13.5-14.25 mpg. Normally I average between 15-16 mpg and that's fine in my book, but this recent mileage is crap. The truck only has 19K on it, isnt throwing codes and seems to be running just fine. Sure is frustrating

 

[Wicked_Sludge]

start with normal tune up items...namely air and fuel filters.

it could simply be due to your filling stations switching to their winter grade fuel...which always produces poorer mileage than summer blend.

 

[DennisH]

Good point wicked. I've heard about that before and have exprienced this myself. Also you may not have thought about this but generally people allow thier trucks to warm up slightly before driving, even if for only a few minutes. And during that time your getting 0 MPG.

 

[Maverick]

I dont know about the "winter/summer blend" stuff. The temperature here doesnt vary enough. I did how ever pull a few plugs to take a look today, and found that the gapp was between .010-.012" too large. I'm throwing new plugs in it tomorrow, we'll see if that makes a difference.

 

[coolman1987us]

I just changed my plugs and the gap was .075, The manual says .042. I noticed the difference in power as soon as i took it for a ride.