How do YOU calculate your fuel mileage?

[BigBore]

I've seen some pretty wild fuel mileage claims on message boards, and I'm wondering how some people check their mileage. Some of them are so far-fetched I can't help but think they do something like this:

"Lets see, I've gone X amount of miles, my tank is X amount of gallons, I've used half a tank (according to the not-so-accurate fuel gauge), so that means I'm getting 35 MPG with my Turbo-blown, Super-chipped 9.5L Duratritonstrokemagnum V12 towing my 20,000lb Weekend Warrior!!!!"

 

[Camstyn]

I fill up at the same pump, use the same nozzle, and park on the same side. I fill until it clicks off, then that's it. I do the same drive daily and use ~$35/day in fuel, the refill is very consistent, almost always within 30-35 cents, so I figure it's a good method. Divide miles by gallons and there you have it.

My new pickup's computer detects the fuel mileage and I've found it to be very close to spot-on so far.

 

[bsmith]

I stop calculating mine because the trucks computer was close enough.

 

[dirt bike dave]

I run the tank until the low fuel light comes on.  Then I fill it full, let the pump click off 3 times (this is what it says to do in the Ford owner's guide).   Usually fill up at the same station.

I manually calculate my mileage every tank (don't record the results, though).  My mileage varies alot, even when I think conditons have only changed a little. 

In California, we have lower energy content 'clean' fuel.  On the web I will see people in other parts of the country with similar vehicles claiming way better mileage than I get.  IMO  local fuel quality is a factor.  And just a few more miles per hour on the highway will kill the mpg on a vehicle with lots of drag.

Basing mpg on a partial tank is bound to skew the results.  There was a guy on the F150 board a few years ago that claimed he got 28 mpg in his new truck.  Turns out it was a short trip. He backed way down from the claim when he checked mileage for a full tank. 

 

[BigBore]

Hah, well at least I know you guys are accurate. Thats the way I figure it.....fill up a near empty tank, divide the miles by gallons......voila! Why is that tough for some people to do?

 

[Bandit9]

I think maybe it is hard for them to admit they only get 10 mpg when they just spent $35k on a new truck!

 

[Treejumper]

LOL Bandit!

I wont feel as bad when i buy my $35K truck and only get 10mpg because i'm only getting 15mpg now. :) I calculate like everyone else said. Hear the dinger bell and fill completely up. Then divide it.

 

[ktmboy]

The crazy thing is these EPA mileage estimates: X in the city, and Y on the highway. If your average mileage is anything close to the highway figure you're doing good.

 

[Highbeam]

I always exceed both of those EPA mpg ratings. I do make it a challenge to get good mpg though.

I have been accused of being anal about logging mpg. Every tank I have ever run through the truck has been logged. I have filled the tank every time I have gotten gas in the last 60,000 miles just so I can get the mpg calculated accurately.

Fill it till it clicks and then half power until it clicks again. Gallons divided by odometer mileage yields the mileage down to the hundredth. The next owner will get the book which also includes all maintenance items.

 

[High Lord Gomer]

HB...what ever happens if your wife finds the log book that shows how much you've *really* spent on bike parts over the years?!? :o

 

[Offroadr]

I have used GPS and gals off the pump. Don't know of a way to get more accurate than that!

 

[KelvinKDX]

Originally posted by Highbeam
I have been accused of being anal about logging mpg. Every tank I have ever run through the truck has been logged. I have filled the tank every time I have gotten gas in the last 60,000 miles just so I can get the mpg calculated accurately.

Fill it till it clicks and then half power until it clicks again. Gallons divided by odometer mileage yields the mileage down to the hundredth. The next owner will get the book which also includes all maintenance items.

Same here - i keep an Excel spread sheet for all vehicles with $ spent on fuel, milage, oil changes, repairs....

Always fill tank.

 

[Faded]

Originally posted by BigBore
I've seen some pretty wild fuel mileage claims on message boards..."Lets see, I've gone X amount of miles, my tank is X amount of gallons, I've used half a tank (according to the not-so-accurate fuel gauge), so that means I'm getting 35 MPG ...

I've noticed on many different vehicles that I've driven (made by many different manufacturers mind you) that you'll get 2/3 of your total mileage on the first half of a tank of gas (according to the not-so-accurate gauge). I.E. My Yota will go 200 miles before registering 1/2 a tank, but by empty (18 gallons) I've only gone 300 miles. That would tend to throw off the numbers.

BTW, I drive until it's close to empty, fill it, top it off and then divide the total miles by the # of gallons.

 

[Highbeam]

HLG, I don't record cost. It would just make me sad. I do like the quote..."There's more to life than gas mileage" when attached to a bumper sticker on a truck. I don't track any of this on the bike, the only thing I need to know for the XR is that I run out of gas after about 60 miles.

 

[LoriKTM]

Reset trip meter to 000 at gas fill up.  Fill tank.  Drive until (nearly) empty.  At next gas stop, record mileage from trip meter, fill tank again, and record gallons used.  Divide mileage by gallons for MPG.  Zero trip meter again.  Repeat. 

I don't trust the fuel gage, or the manufacturer's specs on the size of the gas tank.  Our truck is supposed to be 30 gallons, but I know we rarely ever put more than 25 in.   But I know we can safely go 400 miles on the truck, and 300+ miles on my Saturn before filling up again.

 

[Fark]

Originally posted by LoriKTM
Reset trip meter to 000 at gas fill up.  Fill tank.  Drive until (nearly) empty.  At next gas stop, record mileage from trip meter, fill tank again, and record gallons used.  Divide mileage by gallons for MPG.  Zero trip meter again.  Repeat. 

I don't trust the fuel gage, or the manufacturer's specs on the size of the gas tank.  Our truck is supposed to be 30 gallons, but I know we rarely ever put more than 25 in.   But I know we can safely go 400 miles on the truck, and 300+ miles on my Saturn before filling up again.

 

That's how I do it.  Eliminate the variables.

Even if your speedo isn't officially right on, you'll still be able to tell if something is causing efficiency loss.

 

[trailwart]

just some advice for all of you running your tanks down below 1/4 tank. if your fuel pump is in your tank it can die prematurely. your fuel cools the pump and if there isn't fuel coverering your pump it will/can overheat and fail. just my .02 cents

 

[dave186]

My truck has 2 tanks, so when i go on long trips and have both of them full, i can just run one out and see how many miles it gets me. right now my odometer is waaaaay off because i just put in 4.10 gears and havent recalibrated it yet. if i calculated it out now, i would be getting awesome mileage!