I was quite happy with 19 MPG out of my new/old 6500 pound Dodge diesel truck, till I heard that others were getting over 20 regularly.
I started having fun with power additions and the teenager in me escaped. I could not help myself; I had to "sample" the prodigious quantities of torque on a regular basis.
I took a road trip and some town driving on top, about 70/30, and got a solid 21!
I have high hopes of keeping it over 20. The teenager is learning some discipline.
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2007 Dodge Ram 3500 SRW 4x4 with 6MT
2003 TDI Beetle
2002 TDI Beetle
currently parked - 1996 Dodge 2500 Cummins Turbodiesel
Custom cab, auto, 3.55 gears