Where's my MPG going?

[briman]

You make a good point and for the most part I agree. It can fluctuate between 11-13 mpg. I can do little to adjust past that. I can push this Hemi hard and I see little difference in mpg. AC or no AC it gets the same milage. The only thing that really drops mpg is hauling a trailer. The Yaris is very sensitive to driving style and I wish it wasn't. I'd like to see a consistent 30mpg and drive the way a like than 34 mpg when I baby the car and 26 mpg when I don't.

[bugmenot]

I fill my tank till the pump automatically shuts off,But I do realize some pumps wont shut off automatically,or will shut off prematurely.
I know I could probably pump another gallon,if I was willing.
This could possibly affect your mileage up to about 5 mpg if my math is correct.

[b_hickman11]

Originally Posted by bugmenot

I fill my tank till the pump automatically shuts off,But I do realize some pumps wont shut off automatically,or will shut off prematurely.
I know I could probably pump another gallon,if I was willing.
This could possibly affect your mileage up to about 5 mpg if my math is correct.

This has nothing to do with it because you will still be dividing the number of miles driven by the number of gallons pumped. You don't divide it by the size of the tank.

[WeeYari]

Originally Posted by b_hickman11

This has nothing to do with it because you will still be dividing the number of miles driven by the number of gallons pumped. You don't divide it by the size of the tank.

Wrong.

Since you are calculating based on distance travelled and the amount of fuel needed to refill, your calculations can be scewed since the "full" level can differ from pump to pump.

[b_hickman11]

Originally Posted by WeeYari

Wrong.

Since you are calculating based on distance travelled and the amount of fuel needed to refill, your calculations can be scewed since the "full" level can differ from pump to pump.

You divide the number of miles traveled by the number of gallons displayed on the pump. If you only pump 8 gallons into the car then thats what you will divide by. If you only pump 2 gallons into the car then thats what you will divide by. It doesnt matter how big a gas tank is, or when the pump shuts off.

For example, if I have driven 385 miles, and I go to a station to refill, and I pump 10.5 gallons, then my mpg is 36.67. You don't divide by 11.1 or the size of the tank.

Another example, if I have driven 75 miles since my last fill up and I pump 2 gallons in the car to fill it up, then my mpg would be 37.5.

So therefore if YOU fill the car up and you have cleared your trip meter after the last fill up, you should get a fairly accurate mpg reading.

[WeeYari]

Originally Posted by b_hickman11

For example, if I have driven 385 miles, and I go to a station to refill, and I pump 10.5 gallons, then my mpg is 36.67. You don't divide by 11.1 or the size of the tank.

So therefore if YOU fill the car up and you have cleared your trip meter after the last fill up, you should get a fairly accurate mpg reading.

Obviously you don't divide by 11.1

But you get different mpg calulations if one pump shuts of at 10.5 gallons, while another pump could shut off at 10.6

Regardless, for basic monitoring calculations would be fairly accurate, but pumps will contribute to either apparent gains or losses in mpg. We really see it with L/100km monitoring. Its easy for pumps to differ 1/2 litre from each other, and that 1/2 litre is a significant % of consumption.

[jamal1984]

i think your car has problems, it's not about your driving style man, even you drive in cold weather and drive it like a drag racer, you can get at least 28mpg, 22-24? that is totally something wrong with your car, you should take it back and get another one.
I'm getting 33mpg now in cold weather with rough driving. i mean rough rough

[talnlnky]

Originally Posted by jamal1984

i think your car has problems, it's not about your driving style man, even you drive in cold weather and drive it like a drag racer, you can get at least 28mpg, 22-24? that is totally something wrong with your car, you should take it back and get another one.
I'm getting 33mpg now in cold weather with rough driving. i mean rough rough

Since when does it get cold in georgia?

New rule yarisworld... if you can't see snow or ice.... its not cold.

I can see if somebody was driving around mostly city, and aggressively... in say sub freezing temps that they could get less than 25mpg.... especially in the sedan. Tho for most people I think you would have to try.

Worst tank I ever got was 34mpg. I'm sure I could get a 30mpg if I wanted to.

[jamal1984]

Originally Posted by talnlnky

Since when does it get cold in georgia?

New rule yarisworld... if you can't see snow or ice.... its not cold.

I can see if somebody was driving around mostly city, and aggressively... in say sub freezing temps that they could get less than 25mpg.... especially in the sedan. Tho for most people I think you would have to try.

Worst tank I ever got was 34mpg. I'm sure I could get a 30mpg if I wanted to.

geez, probably you get use to snow? but down here if it get 40degree it's cold, and it's icing or frosting entire the car in the morning, and it's took around 2-4 second to drank up the car, that is cold already. i agreed that we don't have alot of hills and mountain road around here, but still the yaris can't get 22-24mpg unless it's got a problem.

[Revsson]

Originally Posted by jamal1984

geez, probably you get use to snow? but down here if it get 40degree it's cold, and it's icing or frosting entire the car in the morning, and it's took around 2-4 second to drank up the car, that is cold already. i agreed that we don't have alot of hills and mountain road around here, but still the yaris can't get 22-24mpg unless it's got a problem.

Maybe you need the Cold Weather Package ??
Or a Georgia Peach to ride along with you ....

[jamal1984]

Originally Posted by Revsson

Maybe you need the Cold Weather Package ??
Or a Georgia Peach to ride along with you ....

man i wish, but it's not an option for my car

[thebarber]

Originally Posted by jamal1984

but still the yaris can't get 22-24mpg unless it's got a problem.

i think i got down to that one tank last winter...350-ish km on a 40L tank....? nah, thats still only like 28mpg 26 at worst.....and that set of time it was like -25C in the mornings.....would let the car idle for 5min +/- then a 15min drive to work in-city.....

[808_Yaris]

can't wait to see how many mph i'll be getting! and
gas is getting cheaper too.

[rningonfumes]

Okay, since the argument is accuracy...

This is what you do:
(if you are looking to compare mileage.)

1. Fill up at the same station and possibly at the same pump.
2. Fill up at the same time of the day, same time of the week.
3. Stop at the click, maybe more if you want to round to the nearest dollar- no more than that. I do it to the next tenth of a dollar.

Divide new gallons into current miles driven. Rinse, repeat. It does not matter how much you filled, nor that you can still even fit 1-2 gallons more, just have to have that consistency.

Edit: And for those who think that they are still adding gas when it clicks, there is such a thing as overflow that goes back to the pump..ie you've wasted gas by trying to overfill. This overfilling can also account for mis-calculations for mpg.

[b_hickman11]

Originally Posted by rningonfumes

Okay, since the argument is accuracy...



Edit: And for those who think that they are still adding gas when it clicks, there is such a thing as overflow that goes back to the pump..ie you've wasted gas by trying to overfill. This overfilling can also account for mis-calculations for mpg.

There is no such thing of gas going back into the pump. Once the noozle flapper is closed, no gas will go back into it. I used to work at a gas station and there are no pumps that suck gas back into them. This is why when you have completely paid for your gas and the pump is turned off, you should re-insert the noozle and give it a squeeze to release the fuel(that you paid for) that was left over in the hose. But it will not go back into the pump.

[roadrunner]

Originally Posted by b_hickman11

There is no such thing of gas going back into the pump. Once the noozle flapper is closed, no gas will go back into it. I used to work at a gas station and there are no pumps that suck gas back into them. This is why when you have completely paid for your gas and the pump is turned off, you should re-insert the noozle and give it a squeeze to release the fuel(that you paid for) that was left over in the hose. But it will not go back into the pump.

Does that mean when I get to the pump it is very likely that there is (free) fuel in the hose that I can get in my Yaris........before I pay to get my gasoline? I should empty the hose......then pay for my normal fillup?

[rningonfumes]

http://www.epa.gov/donttopoff/

Second reason is that you may damage your charcoal canister.

[b_hickman11]

yep, thats why after you have completed the sale, go back to the pump and insert the noozle back into your car. Depress the nozzle and the gas that you paid for, but is stuck between the pump and the noozle, will be drained into your. Therefore you will not be losing money by topping off.