Ok, then if I fill up my tank until the pump automatically stops, is it fair saying that I've have a total of (including what was in their) apprx. 16.4 gallons of gas into the tank? Because I want to get real accurate on the mpg. But the problem is, when my needle won't even move (very VERY bottom), I still have atleast a gallon in the tank. I was able to drive 15 hwy miles the other day when it was emptier than empty (the night before I ran out of gas pulling out of the driveway in the morning). So I suppose that I will just go until the needle doesn't even move, then divide the mileage by 15.5? Is that a fair assumption? This sure is getting complicated!

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)