how many bars to a tenth of a mile?

[ukrkoz]

so, weather is still cold, yes, almost June, and furnace runs at night. but it's getting warmer, and mpg slowly started creeping up. (Seattle)

curious am i, how many full 60mpg bars on consumption screen does it take to get another 0.1 mpg upgrade? so far, i can get 4-6 of them, in a row, and it won't budge. takes average 3-5 days of cautious driving, to get one.

[danealle]

It depends on how many miles you have traveled on that same tank of gas. When you first fill up the tank average changes very rapidly based on your mpg rate because the total miles traveled factor is low.

After you put say 400 miles on that same tank of gas the tank average will change very slowly if at all because the total miles traveled factor is high.

[ukrkoz]

this is true in general, but not in my case. i followed the advice of the wise, and they say - never touch reset button. apparently, only in this manner, one can have true mpg record. i am not sure, but i am more or less on 5-6 mths since i touched reset button. mpg readings are basically frozen. changes are very minute.
before, when i was resetting mpg after every refill, i could get whatever i wanted as the best mpg, even 99.

but since i stopped resetting, it cycled through one tankful, and therafter basically does not change, or changes very very slowly.

but i'd love to have a reward for those "60 mpg" bars on display. the change is so sloooooooooooooooooow though..

[danealle]

Yes. I was referring to the little round display on the dash, it shows tank average for that tank of gas only. I too have never reset the mpg display in the Nav system screen. Therefore the average mpg on that screen is using the total miles driven for the entire life of the car and not for just that tank of gas, thus making the miles driven factor of the equation Extremely high and will take an eternity of solid 60 mpg rated driving to change it.

[ukrkoz]

oh, that one. it's usually 2 mpg higher than one in consumption screen. i forget about in dash one, i keep mine of trip A/temperature.

i wouldn't say it's "eternity". right now, esp when cold goes away, i am getting, considering that i drive TCH only every other day, 0.1mpg improvement in about a week or so. was on 37.2 not so long ago, have 37.5 as of today solid. but now it dropped down to 40 degrees again, so who knows. 40 in Seattle, few days before June - UNHEARD OF.

[danealle]

I would say that the screen on the Nav system is far more accurate because it is using way more data to make it's calculation. It's using the total miles on the odometer factor as well as total number of gallons ever put into the gas tank and also the total average of each tankful (or in your case, totals would be "since reset")

I don't think anyone has ever tested it's accuracy because to do so they would have had to manually record each of those factors since day 1 of buying the car brand new. Thank goodness for computers that record and store all that data for us.

[ukrkoz]

still curious if someone observed how many 60mpg bars does it take for the "average mpg" to move up.

[danealle]

As I posted previously, it will be different for every vehicle because the factors used are based on each individual vehicles numbers. There is no set number of 60 mpg bars to achieve a point change. The gain of a point is determined by 3 factors that will be unique to each vehicle. i.e. the total number of miles driven since reset, total number of gallons put in the tank and the avg mpg rating achieved overall. No 2 cars will be the same.

[ukrkoz]

well, many bars.

i had an opportunity to run 11 60mpg bars in a row yesterday, and it changed nothing.
then i had 30 min stretch with about 80% of it with bars being up in 60mpg or well above 45mpg.
no difference.

i guess, it's simply an invalid question.

[danealle]

What you're not understanding is that in order to change the average of a very high number it would take a very high number of miles at 60 mpg's. as opposed to changing the average of a very low number.

If you have not reset the comsumption screen in a long time then you have a high number of miles that you are trying to change the average of.

Reset and you will see very quick changes.

[ukrkoz]

oh, wow, it moved!! since my last post, drove her once for 40 miles, and more today. crawled up another tenth of a mile per gallon.
ha-ha, i start developing an interesting driving style. if i get another tenth, then i just creep down the road, securing it.
and it's ABSOLUTELY relevant to outside temp. and it still in low 50s am here. who would have thought, i was closing on 40 same time a year ago, when it was normal heat level for the area. now - still creeping up to 38.