Will you get better gas mileage with an almost empty tank of gas?

Fuel adds weight to a car and with a full tank of gas you're burning more gas hauling around the weight of that full tank of gas.


What does gas weigh a gallon?


How can I measure my gas mileage without filling up the gas tank?|||6 pounds a gallon, don't go rushing to the bank with your big savings, lol! You might save 1, 2% tops.





I don't know a way to get a hard measurement of gas mileage without filling up the tank. Even measuring from fillup to fillup isn't perfectly accurate because different pumps click off at slightly different places. Best to average over 2-3 consecutive fillups.|||I dont think you will save too much. The average difference in keeping half filled and full filled tank will be about 6 gallons for a 12 gallong capacity. The six galloins will be about 20 pound - will not make a big difference.





You can calculate the saving on switching to a more fuel efficient cars by checking








http://hestecrv.com/car.php|||There are some diagnostics devices, but they are quite pricey. Why not work out the math? Just run it on the highway with different levels of fuel and record how far down the fuel gauge goes after, say, 10 km? Make sure that only you, the gas, and any needed weight be in the car when checking.