Need help on the Math
 

Literally....one of my weaker aspects is math. Here's a puzzler for you, and one I'm sure others have encountered.

When approaching the state line the other day, my tank was nearing empty. My GasBuddy App....great app for the droid btw to find the gas prices at stations in any given area....showed my greener pastures 20 miles ahead, however, my Empty light and mileage on current tank said there was a real chance I may not get another 20 miles. Not really wanting to run out of gas, at all, but not wanting to pay 25¢ per gallon more for a full tank, I did the ecomodder nightmare and put in just 1 gallon instead of filling up so I could accurately track my mileage.

So when I filled up after the 20 miles, how do I enter my miles & gallons on the fuel log?

I went 432 miles, put in a gallon, drove another 20, there was 452 miles on Trip-O-Meter when I filled up putting 12.3 gallons in the sled. My tank capacity is 13.2 gallons if it means anything.

Any advice?

452 miles and 13.3 gallons.

That's what I figured, then I freak my self out with this thought.

I get close to 40mpg say, so when I put in the 1 gallon and go 20 miles, I figure I burned about 1/2 gallon of gas. So when I put in 12.3, and add the half gallon I used, that would be 12.8. I didn't use the whole gallon of gas.

Sorry, but when you give an answer here, in order to get it sorted in my over thinking skull, I'm going to need an explanation for the logic of how you arrived at your answer.

all you do is not reset your trip meter. when you go to fill up you add the gallons filled from both stops together then just calculate your mpgs like normal

I'll just leave you with this to ponder on: Where did the other 1/2 gallon go? ;)

Your correct here, though go with your average posted 35.3 mpg so 20miles/35.3 miles/gallon=.57 g then 12.9 g

however the problem is that since you drove farther then the last time you filled up you used more then 12.3g. plus another .57g haha even if you fill up at the same point every time there is always going to be a high tolerance without actively flowing the volume used.

I got 15 gallons of gas @ $3.199 a month ago. I filled the motorcycle until the 5 gallon can was empty then logged the mileage. One can was perfect, the whole can for the last refill.
The other can was not quite enough so I went to the station and topped it off. Every time I refilled I wrote the mileage down on a piece of masking tape on the cabinet in the garage. When the can was empty I knew the mileage for 5 gallons, which was more than the tank capacity.
I would just consider the trip odometer. When you refilled and reset the trip meter, that is the point where you calculate the mileage from one trip reset to another, unless you just record odometer mileage when you refill.
Since you waited until you completely filled the tank to reset the trip, that is where the calculation occurs. 1 gallon earler and the rest when you got to the station with a better price. The total of both fills is your refill amount since that is when you reset the trip meter.

regards
Mech

I would have pushed on for the cheaper station without stopping. However, if you do the math, you will see that you consumed 13.3 gallons in your 452 mile trip. Your tank only holds 13.2 gallons, so you would have run out of fuel about 3 miles away from the cheaper station... you would have seen me jogging on the highway with an gas can.:snail: Clearly you made the right choice. :thumbup:

I've stopped to put a gallon in at an expensive station before, not knowing if I could make it to the cheaper stations. With my UG now installed and calibrated, I can push things a lot more comfortably. My fuel light comes on when there is well over a hundred miles left on the tank!

I was wondering about the math! :)

My low-fuel light does not come on...

I learned to not wait.

add up all the miles, add up all the fuel.
then do the calculus.