How do you know how many gallons you've used? I can figure out the math part I'm not that

 

What I do is when I fill I up, I write down how many miles I have on my odometer. THe next time i fill up I write down the number of gallons I have used, then write down my odometer reading again. Subtract the first odometer read from the later one and divide by the number of gallons. So an example:

78,000 miles when I fill up
78,290 miles next fill up
Filled up with 11.6 gallons.

78,290-78000= 290
290/11.6 = 25mpg (and no, thats not what I get)

 

I see you've got some tire related mods in your future.
With a wider tire you'll be getting different mileage so you can use some of your Algebra and get the speed ratio off of a tire calculator from tire rack or some other place like that and do your final MPG calculation.

I went into some detail with the math on another thread, I'll see if I can find it.

 

i fill my tank and set the gas. odometer to 0. when i fill up next time i know how many miles i've gone on that tank. i take that number of miles and divide it by the amount of gas i just put in.
Ex.full tank
drive 215 miles on it.
fill up tank with 14.49 gallons of gas
215/14.49= 14.84 mpg.

i hope this is how it's done if not oh well sorry.

 

Okay here's the text of it:

Use the tire calculator that you'll find at different places and plug in any number to see what the ratio will be and then use the math.

For example:
Let's say you're guage shows you're got 90 miles out of the last 9 gallons. Go to the calculator and put some number like 60 mpH to get the actual mph - let's say 80.

SO to get your mpG it's going to be a ratio thing

plugged in mpH/actual mpH = your stock mileage/actual mileage

in this case...

60/80 = 90/actual mileage

if you don't remember your Algebra

60/80 x 80 = 90/mileage x 80
60 = 7200/mileage
60 x mileage = 7200/mileage x mileage = 7200

(60 x mileage) / 60 = 7200/60

mileage = 7200/60 = 120
Voila!

*EDIT*
Sorry if this came off as pedantic. I'm not sure what the math skill levels are for people here. I know older farts like myself can always say "I forgot" over "I don't know" like you young'uns

 

Thanks for all the info but all i need to know is how to see how much gas Ive used. I know how to do the calculations. I just dont know how to determine if how much gas in gallons ive used.

Say i fill up then go until i get to E. Now i go fill up again and it takes say 14.8 gallons to fill. Does this mean ive used 14.8 gallons since last fill up? I know how to calculate MPG and all that.

 

So long as you had filled up all the way the time before, then yes, you would have used that 14.8gallons.

 

Cool. So I guess thats how everyones doing it. Thanks guys!!