What's the average of 5 MPG and 10 MPG?
The math isn't quite obvious to me, but if you go out camping and get 5 MPG on the way to the campground and turn around and get 10 MGP on the way back, your average MPG won't be 7.5 as you would expe...
Forum Discussion
For practical purposes... Every time I fuel up (fill) I write three things on the top of the receipt...
Mileage on cumulative odometer
Engine Running Hours
Engine Idle Hours
The receipt will have the quantity (gallons), price per gallon, and total price. I also note the location, time and date which are also on the receipt.
I enter all of that into a spreadsheet. From that I can get calculations that are good enough for 99% of non-math-geek humans. I can calculate MPG :E per tank and keep a cumulative count of total miles and total gallons of fuel, average MPG, average price per gallon, high price per gallon, low price per gallon, etc. I also know all of the locations where I got fuel, and what my engine hours and total mileage were at the time.
:D
Mileage on cumulative odometer
Engine Running Hours
Engine Idle Hours
The receipt will have the quantity (gallons), price per gallon, and total price. I also note the location, time and date which are also on the receipt.
I enter all of that into a spreadsheet. From that I can get calculations that are good enough for 99% of non-math-geek humans. I can calculate MPG :E per tank and keep a cumulative count of total miles and total gallons of fuel, average MPG, average price per gallon, high price per gallon, low price per gallon, etc. I also know all of the locations where I got fuel, and what my engine hours and total mileage were at the time.
:D
