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On my way to Vail, CO yesterday my son and I were shocked to watch the last 50 mile average to creep up from 30s to over 40 MPG. What a car to drive on a gorgeous day in the mountains of Colorado.
Fill up the tank, drive for 3 hours. Fill up the tank again. Note how much gas it took to fill the tank. Divide the miles driven by the amount of gas used.
Come back to me with numbers over 30 and I'll be impressed. Hell. I get 99 MPG when I lift going downhill on instant gas mileage.
That "last 50 mile" average, as Shania said, "Don't impress me much".
Regardless of what the computer says, I just don't believe any of these stories are accurate. The ONLY way to compute this is to measure what goes in then what comes out. The computer is reading different things for different cars, all else being equal. The best think to do is to just not pat attention to fuel mileage. I personally would worry about a dangerous lean condition if I got mileage that was was off of GM's charts.
I have seen 39 before.I believe it's possible to get 40 and not have downhill all the way.
NBC ,or ABC did A story on gas mileage A few years ago.Driving from I believe Detroit to
New York City.Ordinary car,I believe it got around 75 MPG.
The one problem I have with calculating gas mileage based on how much gas you put in at the pump is that you don't know for sure if the pump has stopped at the exact same point as it did the last time you filled it. So you really need to calculate it over many tankfuls in order to be totally accurate. Another factor is the outside temperature, because the amount of fuel you are getting will vary a lot from a hot day to a cold day. Since the pump is volume corrected to 15C, the amount of fuel you get will be most accurate when the temperature is at that point (at least underground, where that measurement is most likely taken)
All that being said, I totally trust my onboard computer, because in the case of my C6 I have double checked over many tankfuls to see how accurate it is and it's right on the money, right down to the tenth of a MPG.
Fill up the tank, drive for 3 hours. Fill up the tank again. Note how much gas it took to fill the tank. Divide the miles driven by the amount of gas used.
Come back to me with numbers over 30 and I'll be impressed. Hell. I get 99 MPG when I lift going downhill on instant gas mileage.
That "last 50 mile" average, as Shania said, "Don't impress me much".
Elmer
I drove mine 590 miles each way from Ohio to NC last week, I got over 31 when I calculated it by the method you described. It was identical to the displayed mpg on the dash btw.
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That's good for a 50 mile average, and if you could duplicate it for a much longer distance, then I would be really impressed. Still, nice economy car you have.
Not sure how accurate it is but I've done a best 33.2 50 mile average with no AC on. This is rolling hills of Iowa driving, so real world up down up down ect. 4cyl mode seems to be worth 3 mpg. Could be tweaked to be more aggressive I think. In the typical rolling hills of Iowa you miss about 1000ft of driving distance by the time it reacts to level or downhill driving so it's on maybe 1/3 the time. In my M7, 7th is also good for 1 or so mpg, and AC takes away about 2 mpg.
Now he needs to turn around and go back the same way and add them together and divide by 2...then it goes back to 24...
I remember looking at it again when I returned to Denver and it was in the low 30s, don't remember the exact number. It's worth mentioning that I-70 traffic on Sunday afternoon was a parking lot. Anyway, I thought 40.9 was pretty cool for driving in the mountains gaining about 5000 ft. elevation. Now it's time to enjoy a cigar and wash the bug juice off.
I remember looking at it again when I returned to Denver and it was in the low 30s, don't remember the exact number. It's worth mentioning that I-70 traffic on Sunday afternoon was a parking lot. Anyway, I thought 40.9 was pretty cool for driving in the mountains gaining about 5000 ft. elevation. Now it's time to enjoy a cigar and wash the bug juice off.
. Another factor is the outside temperature, because the amount of fuel you are getting will vary a lot from a hot day to a cold day. Since the pump is volume corrected to 15C, the amount of fuel you get will be most accurate when the temperature is at that point (at least underground, where that measurement is most likely taken)
Two things: First, since the fuel is stored underground, the actual fuel temp doesn't vary nearly as much as the outside air temp. Two, what's your source for pumps correcting volume? Every gas station in my area has stickers on the pump that say volume is not corrected for temperature, and that the energy content of the fuel dispensed may vary with temperature.
Love driving mine in the mountains here, although I never look at or think about gas mileage. I keep mine in Sport mode and paddle shift and couldn't care any less what the mileage is.
The volume of a liquid like gasoline won't vary enough with typical temp changes to notice or measure. It's a liquid, not a gas.
40.9 mpg!
