I've been trying to hunt down some ways to improve the fuel economy of my 2004 Dodge Durango 4.7 SLT AWD. It's well maintained and only had one owner before I got it. Runs perfectly fine, but I have always had one thorn in my side about it: the horrid gas mileage. If I run on 87 octane, I only get 10-11 mpg city and 15 on the highway. I've got to run in on 89 octane to get the 12/17 it was rated for. Sometimes even that doesn't work. I don't drive with a lead foot or even use AC, and I keep it well maintained. Anyone had better luck with squeezing close to 15 city and 20 highway out of one of these, or is it even possible? I'm sitting at right around 124k miles and I run synthetic oil, if that matters.