Using too much fuel?
I've noticed this since I bought the truck back in 07...but does anyone else's truck burn alot of fuel when you let it idle for more than 10 minutes? I always let the truck warm up before I drive it...and if I'm anywhere off the Full mark, it seems I always notice the needle has dropped almost a 1/4 tank from just idling...sometimes it goes back up but it usually doesn't. I've let it idle at rest stops sometimes on road trips and lost a lot of fuel...is this normal? My buddies Cummins burns like 1/8 of a gallon when it idles 8 hours...HELP!