How do YOU calculate your MPG
 

so i did a search on calculations of MPG on the board and did not find anything in terms of a formula...

How do YOU calculate your miles per gallon?

My method:

1) Fill up with 91 Premium
2) Reset Trip Odometer to 0
3) Drive till my yellow light comes on
4) Repeat item 1
5) Divide Number of Miles Driven Indicated on my Trip Odometer by the Number of Gallons filled into the gas tank


ANY OTHER METHODS ? ? ?

thanks
jimbo

That is exactly how I calculate my MPG. I wouldn't change a thing. :)

come on -- i'm sure there's more than one way to skin a cat!

at least i'd like to see if anyone has been doing the MPG thing with some interesting methods for entertainments sake...

Fill the car.
Reset the trip.
Drive as much or as little as you like.
Re-fill the car.
Divide milage into amount of petrol you just put in.

The most accurate way is to continue to add miles and gallons over three to four tankfuls. There is too much variation in the shut off valves at the pump, and too much variation in driving styles, weather, etc. to get a good reading on one tank.

1. Start with a full tank
2. Set odometer to 0
3. Drive 'til your refill point
4. Fill it up
5. Record the gallons
6. Repeat steps 3,4,and 5 a couple of times while letting your odometer add up all the miles.
7. Fill up a final time, add those gallons to your overall total, then divide the odometer reading by the total gallons.

I just got out of my lease on a Ford Excursion (Triton V10), so measuring MPG became an obsession.

The best way IMO, as mentioned here is NOT to use your fuel light or guage.

Do the following.

1. Fill tank to full with no topping off.
2. run as many miles as you like (the greater the miles the less error in calc.
3. at next fill up record miles run (example 200 miles)
4. record amount of gallons required to fill tank (example 10.8)
5. reset trip meter and repeat steps 1-5 again

In this example the first fill up: 200 miles requiring 10.8 gallons to replinish equates to 18.5MPG.

Your accuracy increases by adhearing to the following:

1. use the same pump at the same station.
2. do not top off the tank.

Measurement error will decrease by law of averages by repeating the measurement over many fill-ups.

I also make a comment on my logs as to type of driving, ave temp or any exceptionals e. g. oil changed.

I do all my calcs this way

Uh, no, there isn't! Other than minor variations (ie fuel light doesn't matter, and more distance makes the results more accurate, or averaging over several fills as described), that is the only way to really calculate mileage. This talk about distance per 'tank' is hilarious, since a 'tank' is by no means an accurate unit of measure and is completely useless.

Regards,
Gordon

Wow $2+ for a gallon of gas in California? And I thought $1.60 was bad.

I was reading mx6.com forums and one guy was concerned over his gas mileage so he calculated his mileage by:

"I also researched on how much mpg i get. I waited until my car ran out of gas, then filled it up with 1 gallon. Now www.fueleconomy.gov said i should get about 19-21 MPG, it burnt off at about 16 miles............ "

1. Running his car till it conks out!
2. Fill with ONE gallon.
3. Resets trip odo.
4. Drive till it conks out again!
5. Reads miles driven!

How could it be any easier! What some people (read numbskulls) will do to avoid that tricky division... ;)

I did my first long (250 miles) highway trip last night and I noticed that like most cars the gas gauge is non-linear. Before I go out and measure, does anyone know what 3/4, 1/2 and 1/4 on the gauge relate to in terms of actual fuel tank contents?

i noticed that at half a tank i can put in about 28 L in a 60 L tank, so a bit less then half.

I use this with my Zaurus: :D

http://www.killefiz.de/zaurus/showdetail.php?app=941

Also track other maintenance with it (oil changes, tire rotation, etc)

--SL01

$1.97 for a gal of exxon premium where i live, was at 2 bucks for a while then went to 198 now 197.
anyway, what i like to do is divide my miles by my gallons:D
________
RHODE ISLAND MEDICAL MARIJUANA DISPENSARIES

we all agree OMG

Does the RX-8 instrument cluster have a "diagnostic mode?" On some cars (e.g. my Cobra) you can display all sorts of useful information, including engine temperature, oil pressure, fuel level, and any trouble codes, all in "raw" form (i.e. the way the come in from the senders) rather than the "cooked" display you'd get from the gauges.

Alternatively, the same data might be available through the OBDII diagnostic port under the dash; someone with a reader might be able to work up a mapping.

HTH!

Ummm.... with a TI-99? (and no, I do NOT wear a pocket protector!)

ok i learned two things from this thread...

1) i should look at the average MPG over a number of tanks (ie 3-4 fillups) instead of the PER Tank MPG

2) some people have spent way too much time tracking their MPG. as far as i'm concerned, as long as i get from Point A to POint B with the big grin on my face from being in my RX-8 i don't really give a rat's a$$ what i'm getting in terms of MPG. if i really wanted a fuel efficient car i'd be in a Toyota Prius or Echo...

Good point. I am or was among the guilty parties but I have concluded no matter what I do i'm gonna get around 17 mpg so what the hey. I had a chance to turn in the car and decided 17 sucked but was "good enough" and there's about a jillion things I like about the '8 so I kept it. That said, i am officially no longer tracking my mileage; I'm gonna start having some fun and living a little which, after all, isn't that why we all bought the darn car? In about 6 months, or if a fix comes out, I will check mileage again just for due diligence but until then hasta la vista on the mileage discussions. :D And if you see a blur in your peripheral vision that's me no longer sweating gas mileage. :cool:

that is some serious logging! good game, jdl. I thought I was bad (ie nerdy) with my logging of the date & location of each 1,000 miles.

back to the point, FWIW, i do a per tank average for my car, and I just keep a mental note of the trend... my mx-6 v6 gets averages b/n 26 and 26.5 mpg. now the weather's cooling down and my AC is off (more often), I just got 27 mpg. man, the RX-8 mpg is gonna hurt me. :(

I just use a cigarette lighter and peer down the fill pipe. Works good so far...

Ah the first fellow MX3 V6 owner I've seen on the forum - hi!

I'm also getting bang on 26mpg this side of the pond, no aircon on mine.

Its the worlds smallest V6 at 1.8l but also one of the sweetest, loves to rev up to the 7500rpm limiter, great handler, pretty practical, can just about get two adults in the back when needed, and good amount of luggage space. So the RX8 was the only replacement for me.

Cheers
---Dave

It can/does vary from car to car.

I use Highway Manager on my Visor Prism. It allows me to track gas and servicing expenses, and tracks MPG per tank, by category (city/highway/sport/etc) and overall:
http://www.snikte.net/images/dsc01561.jpg

It will also graph the MPG (green line is the average):
http://www.snikte.net/images/dsc01562.jpg

For our international friends, it will also do metric units, including l/100km.

that is too cool eccles