1) '05 Sport CRD 4X4
2)5 speed auto w/lockup, 545 RFE
3) 3.73
4) Aero Turbine 2525 muffler, Provent CCV filter, Shell Rotella 5W40 oil, B20 biodiesel when I can get to the station or premium #2, stock tires at 40 psi, plug in block heater when it gets below 40 F.
5) 25 plus combined / 32 highway, 6500 miles on vehicle.
Quality of fuel makes a HUGE difference with this diesel. On a recent trip to Texas, with both B20 biodiesel and Diamond Shamrock #2, it easily achieved 32 mpg average for the tank (no overhead console) at 75 mph over some not-so-flat terrain in the mountains of AR, TN, and NC (along I-40). Shell #2 averaged around 25 or slightly better highway, Citgo and Exxon #2 from TN and AR respectively flat out sucked, 22 or less highway. Currently trying a tank of Hess #2 before going back to bio, supposedly a good grade of premium in this area of NC. Looks promising so far, 85 miles of combined driving and the fuel gauge needle is still pegged!
So far, here's my grading of the different brands of fuels -
Poor MPG - Chevron, Citgo, Exxon, BP Amoco
Medium MPG - Shell
Best MPG - Diamond Shamrock/Valero, B20 biodiesel (retail straight from pump)
Pending Evaluation - Wilco-Hess
Ditching the incredibly restrictive stock muffler and installing a straight thru design has made a dramatic difference in performance and MPG. Bottom end performance is where the difference seems to be most noticeable, and my combined MPG for my daily commute has went up by almost 3 MPG!
The stock muffler is necked down to 2" at the inlet and outlet, and is baffled out the wazoo. It's the same muffler they use on the 3.7 V6. Hey, 3.7 guys, that might be something worth trying, ditching the stock muffler in favor of a high flow unit, might pick up your MPG's as well.