One of the YouTube channels which I regularly watch is the Adept Ape channel...How he reached his choice of usernames is a mystery to me, but he seems to be a very intelligent as well as thorough and inquisitive Caterpillar diesel mechanic...Today's video concerns trying to gain better fuel mileage with diesel tunes...The specific vehicle in concern is a Peterbilt with C15 Cat @ 475HP pulling 80K pounds consistently...The driver complains of getting an average of 3.8 MPG...The equation he introduces is MPG per 1K pounds, calculated as gross weight X mileage ÷ 1000 = fuel mileage per 1K pounds...In this case: 80,000 lbs X 3.8 MPG ÷ 1,000 = 304 MPG(1K#)...Extending the math to Honda hybrids and motorcycles the Pete is far more efficient...Using the math on my mighty Dodge/Cummins I get 7500 X 12 = 90(1K#)...12 MPG is about average city/hwy for me with my 4.10 gears...That makes me feel only slightly better having dropped $350 at the pump last week at my quarterly fillup...Here's the video......Ben