Fuel Economy

[BMGYaris]

Originally Posted by regulus

so best thing i guess is start counting from the second bar until the 7th vanishes. Ill try that

I never meant to ignore the first bar in your calculations. I just meant that the gas fuel guage is not precise, it is just rough estimates as to how much gas is still left in your tank. Thus no bar or number of bars represents exactly what it does mathematically (mathematically each bar equals 1.387 gallons, but in reality it will not drop at that precise moment). Suppose that on your first bar it was off .21 gallons off. that would be something about 15% more fuel consumed than what you mathematically yield should have been used on your first bar. But the more bars that are gone then the less the margin of error impacts your calculations.

So what this means is that on one bar the margin of error is going to represent some range of fuel consumption, lets say anything from 5-25% more than what you would expect that first bar to actually represent. However, as you use more gas, the actual margin of error (say .21 gallons) should remain pretty consistent (within a range). That means that if .21 gallons creates a 16% inaccuracy when guestimating from your first bar, you will find that the % inaccuracy decreases as your fuel consumption increases. Thus as the total gallons consumed increases the error will represent a smaller portion of your gas consumption. Meaning the more gas consumed the more accurate your bar guage will be, though no one particular bar will be any more accurate than any other. You should always calculate with all available information

Note: im only talking about rough guesstimating before fill ups. Obviously the only way to get true readings is to fill up many times at the same pump. I just didnt want him too be too shocked when his 35 mpg city turned in to 29 or 30...hopefully 32.

[regulus]

Thanks both for the info :D

Ill keep you posted

[swng]

You are welcome and good luck!
BMGYaris' advice makes lot of sense to me. I admire the meticulous calculations.
In my layman's language, all bars do not necessarily represent the same amout of fuel and hence mileage. Depending on how full the tank is filled up, the first bar usually represents anything from more to a lot more fuel than the others. Trying to estimate a car's fuel economy with the data collected from just one bar can lead to a rather unreliable result. The bigger is the database, the better.
Long term averaging and consistency in filling up location(s) and method (I would say) can help minimize the effects of many possible errors.
Good research friends!

[keesue]

Very first tankful = 35.6 miles/gallon

[swng]

The result is quite good keesue, considering that it's your first tank and that winter has arrived (weather should not be severe in San Francisco right now though). I presume you are reporting in miles per US gallon. That will be more than 42.5 miles per Imperial gallon.
Please keep on posting your results from time to time and describe your driving style and the traffic and load conditions leading to your results every now and then if you don't mind.
Thanks!

[keesue]

I sure will. These miles are 85% commuting. I drive at an average of 65 miles/hour. I expect, as the engine breaks in, to get another mile/gallon. I'll keep you posted.

[swng]

Originally Posted by keesue

I sure will. These miles are 85% commuting. I drive at an average of 65 miles/hour. I expect, as the engine breaks in, to get another mile/gallon. I'll keep you posted.

Thank you in anticipation keesue!

[spkrman]

average of 30 mpg over almost 4 gallons, lots of idling (approx 30-40 mins worth)... lots of agressive driving/acceleration, and mostly city miles... pretty awesome given the circumstances!

BP regular gas, btw.

[SimplyYaris]

First tank of gas - 80/20 city/highway 36 mpg. Yes!

[swng]

Latest Tank (not good because of up to 35% of hilly/stop and go city driving):
Fuel Cost
$37.66 (Canadian)

Distance Travelled
533.9 km
331.77 miles

Fuel Amount
39.07 litres
10.32 US gallons
8.59 Imperial gallons
Cost of Fuel
$0.96 per litre
$3.65 per US gallon
$4.38 per Imperial gallon

Fuel Economy
7.32
litres per 100 km
32.14
miles per US gallon
38.61
miles per Imperial gallon

Mileage Costs
7.0538
¢ents per km
11.35
¢ents per mile

[gonzo452001]

my last tank of gas i got 43.1MPG But this tank isn't going to be as good bad weather having to run my deforst a lot wish that had't linked it to the a/c

[palsan]

Originally Posted by gonzo452001

my last tank of gas i got 43.1MPG...

I'm assuming from your profile that you are in French Lick, Indiana, so I'm guessing your numbers are in US gallons. So, how is 43.1MPG (5.46L/100Km) possible? (If it's imperial gallons I apologize in advance)

Have you stripped the interior of the car, removed the seats, removed the spare tire, stripped the paint, ... ?

I mean, Toyota rates the car as follows:
Manual (city/hwy) 6.9/5.5
Automatic (city/hway) 7.0/5.6

Real world results are normally worse than the manufacturer spec sheet, yet you are reporting BETTER results than the 100% hwy numbers. How is that possible?

[argylesocks]

Originally Posted by palsan

Real world results are normally worse than the manufacturer spec sheet, yet you are reporting BETTER results than the 100% hwy numbers. How is that possible?

my BEST tank was 44.2mpg (US). this was a full tank which included a drive to Vermont with my girlfriend, my bike/wheels on the back & all my gear in the car.

I drove 58-60mph the whole way & coasted in neutral down every hill.

This summer i was consistently getting 40-42mpg without too much effort other than keep my highway speeds to 60mph & coasting when i could.

Lately, due to cold weather, warm-ups, & some faster speeds, i have been more in the 38-40mpg range... still acceptable :)

[swng]

Under very very favorable conditions, I guess it may be possible to get better than published fuel economy. However, with the traffic conditions that I have to go through daily, I won't even think about it.

[gonzo452001]

yes US gallons totaly stock except for the scan gauge there was about a 150mile trip on that tank also and i hardly ever drive over 60mph and alone most of the driving got 42.5 on the first tank use sunoco 87 regular gas i am real happy with the car

[spkrman]

over a 400 mile trip, and some 30-40 miles of city driving... 36.6 mpg. driving conservatively, motor only has ~1600 miles on it, 1600 after the trip that is.

[swng]

Originally Posted by spkrman

over a 400 mile trip, and some 30-40 miles of city driving... 36.6 mpg. driving conservatively, motor only has ~1600 miles on it, 1600 after the trip that is.

You drive a lot!
Congratulations on the improvments made over what you reported the last time!
The long trip and the conservative driving style must have helped.

[spkrman]

Originally Posted by swng

You drive a lot!
Congratulations on the improvments made over what you reported the last time!
The long trip and the conservative driving style must have helped.

yep, mileage is also improving as motor continues to break in, first tank was approx 32mpg driving conservatively.

The past few weeks have been sorta abnormal - lots more driving than usual. Even though i've done over 1500 miles in the last week, its more than likely that I won't go over 12k over the next year. Although, a trip to NY is coming up... 1600 more miles lol.