99 Ram 318 4X4 Mileage

[90sabre]

Hey everyone, I know this is a touchy issue, but I'm just wondering what others are getting for mileage. I have been getting between 12-13 mpg with a combo of city and highway driving. On a good day I might get 14 on the highway. I've done a recent tune up, tire pressure is at 42. Part of the trouble could be that I warm it up for about 10-15 minutes every morning as it's been quite cold. Also, anyone try the tailgate thing? I know mythbusters pretty much proved that tailgate on and up is better, but I was wondering if this could vary with diff truck models.

Thanks!

[crazys182003]

got an 01 1500 4x4 with a manual tranny and get about 11.5 average winter and 12-13 average summer and ocasionally up to 15 highway. Tires are P285/75R16 all terrains at pressure of about 45 psi.