This is how I'm calculating the gas mileage in my car.
Someone's trying to tell me I'm doing it all wrong. [roll]
Last fill up mileage: A
Mileage this fill up: B
# of gallons of gas pumped in: X
B-A = miles/gal
X
Here's the twist; I don't always fill the tank. I don't think it matters, B says it definitely does.
What do you think??
it only matters if you dont consistently fill her up to the same point in the tank.
It does matter.
Take your example.
Start at 0 miles, drive 300.
Stop for gas, and put in one gallon.
(300-0)/1= 300 miles/gallon.
That's how I calculate my mileage but I fill until the pump stops. Assuming that every pump stops at the same "full" level, I feel that I get an accurate estimate of my mileage. Assuming that you top off to the nearest $.10 or something like that, the formula will not give you "accurate" results. You need to put in a full tank in order to calculate how much gas was actually used for the distance covered. Otherwise you're overestimating your mileage, as given my Mr. I's example.
No you have it right no matter how you figure it. You only fill up what you drove. So what you put in the tank represents what you used. So that number will tell you how much you used previously.
Quote from: Latinbalar on January 27, 2010, 09:48:40 AM
So what you put in the tank represents what you used.
Only if you fill up to the point where you stopped last time. The logical place would be when the pump automatically stops.
Trust me.
I'm an engineer. ;D
The OP's formula will work, given the following:
Gas tank was full at mileage A.
Gas tank is full at mileage B.
X, the total amount of gas, is the *total* amount pumped in between mileage A and mileage B.
-------------------------
If you partially fill between mileage A and the fill-up at mileage B, then you've got to add that to the fill-up at mileage B to get a correct value for X.
I can sell you some magnets to put on the fuel line-they align your hydrocarbons and make you get way more better mileage. :D
don't for get that tornado thingamajig that swirls the air in the intake.
[/quote]
Quote from: Randimus Maximus on January 27, 2010, 10:12:21 AM
don't for get that tornado thingamajig that swirls the air in the intake.
So much for my sales pitch... thanks Randy! >:(
There's no conveyor belt involved here, right?
Quote from: Speeddog on January 27, 2010, 10:15:26 AM
There's no conveyor belt involved here, right?
It doesn't matter-the car won't take off.
must be the meds, not sure why I spelled "forget" as "for get". :-\
The better way to do this:
Gas tank was full at mileage A.
Ride till you have 5 or 10 fill ups
Gas tank is full at mileage B.
(B - A) / total gas = better average
This way, you get a better measurement of gas consumed and therefore more accurate MPG.
Quote from: MrIncredible on January 27, 2010, 10:16:03 AM
It doesn't matter-the car won't take off.
<skeptical>
(http://static.blogo.it/autoblog/mercedes_clr_flip.jpg)
Quote from: Speeddog on January 27, 2010, 09:57:52 AM
The OP's formula will work, given the following:
Gas tank was full at mileage A.
Gas tank is full at mileage B.
X, the total amount of gas, is the *total* amount pumped in between mileage A and mileage B.
-------------------------
If you partially fill between mileage A and the fill-up at mileage B, then you've got to add that to the fill-up at mileage B to get a correct value for X.
I agree with this one.
Why would this be wrong Dave?
Quote from: Speeddog on January 27, 2010, 10:19:41 AM
<skeptical>
(http://static.blogo.it/autoblog/mercedes_clr_flip.jpg)
Clearly this only works if you use Mobile 1 too
Quote from: Monsterlover on January 27, 2010, 12:40:06 PM
I agree with this one.
Why would this be wrong Dave?
That would work just fine.
Quote from: MrIncredible on January 27, 2010, 09:40:03 AM
Start at 0 miles, drive 300.
Stop for gas, and put in one gallon.
(300-0)/1= 300 miles/gallon.
Wow - excellent mileage - that's what I'll start doing [thumbsup]
Quote from: Monsterlover on January 27, 2010, 12:40:06 PM
I agree with this one.
Why would this be wrong Dave?
I said her method is wrong-not the one you quoted.
[popcorn]
Thanks guys. :D
I don't fill up all the way b/c I think my tank has leak on the top side.
I consistantly put $20.00 in, but the amount varies due to the flucuation in gas prices.
Guess I'll never know my true mileage. :-\
Quote from: DesmoDiva on January 27, 2010, 06:12:55 PM
[popcorn]
Thanks guys. :D
I don't fill up all the way b/c I think my tank has leak on the top side.
I consistantly put $20.00 in, but the amount varies due to the flucuation in gas prices.
Guess I'll never know my true mileage. :-\
It's all an exercise in futility if your tank is leaking it out. :P
Quote from: DesmoDiva on January 27, 2010, 06:12:55 PM
[popcorn]
Thanks guys. :D
I don't fill up all the way b/c I think my tank has leak on the top side.
I consistantly put $20.00 in, but the amount varies due to the flucuation in gas prices.
Guess I'll never know my true mileage. :-\
if your riding those 4v 998/999 motors in your sig, then i dont think youd really care to know. those thigns are gas hogs.
Quote from: DesmoDiva on January 27, 2010, 06:12:55 PM
[popcorn]
Thanks guys. :D
I don't fill up all the way b/c I think my tank has leak on the top side.
I consistantly put $20.00 in, but the amount varies due to the flucuation in gas prices.
Guess I'll never know my true mileage. :-\
That's alright, knowing your mileage won't really change your driving habits, will it? I know when I'm getting poor mileage because I'm speeding. I just don't care. I want to get there faster and don't mind paying a bit more coin to save more time.
Quote from: He Man on January 27, 2010, 08:19:40 PM
if your riding those 4v 998/999 motors in your sig, then i dont think youd really care to know. those thigns are gas hogs.
The mileage I'm talking about is for my cage.
Quote from: MrIncredible on January 27, 2010, 06:36:59 PM
It's all an exercise in futility if your tank is leaking it out. :P
I know. Just trying to nurse the car through the winter.
The volvo I am borrowing right now has an instant and an avg MPG reading on it and it is very distracting for me. The instant MPG is fun because I try to see how little I can get. Slamming on the gas at 5000rpm I get 3.7mpg. It only goes up to 99.9mpg which is easily obtained by coasting. I had to change the info to exterior temperature because I was watching the MPG and not the road.
The MPG display in the wife's VW does the same thing, although it goes down to 3.4 (reading the manual shows that it is the lowest reading it will show). Coasting downhill will show 160mpg+, but it quickly goes to ---.
Stomping on the gas in sport mode, I'm not sure I'd want to know how fast the 4.2 V8 is sucking the gas down...