One thing to note:

When averaging several tank-fulls for calculating mpg, don't just find the mpg for several fills and average those numbers.

Add up all the miles and divide by all the gas put in.

Otherwise you're taking a weighted average of unweighted numbers.

(for example, if you have 30 29 31 24 but the 24 fill was more gallons because you ran the tank way low before that fill, you're not giving it full credit).

 

Key word - "accumulating".

 

The Scan Gauge is not alway right, but it does give you an idea whats going on. I have 4 settings that I see MPG, Average mpg, gallons per hour, timing. The mpg is suppose to be whats going on at that second, Average and gallons per hour are self explanatory. ScanGaugeII - Trip Computers + Digital Gauges + Scan Tool . On some cars you can see A/F, fuel trims. Honda does not or dont know the code to read it.

I always do it the old fashion way, but I compare it to the scan gauge which should be accurate. When you fill up you put in how much fuel, so thats the correction factor. The station could be stealing gas too. Like I said that I filled a 1 gallon can and use 1.05 added 8 oz oil and 4-5 oz of gas already in there, so that adds up to a gallon per 10 gallons.

 

I filled up a few weeks back when the temperature was in the upper 70s and $2.91 a gallon.. I had driven 310 miles and had 1/4 tank left according to my fuel gauge when I filled up to the top of the fill tube with 10.9 gallons at $3.31 per gallon and the temperature in the upper 40s... I got around 29.5 MPG which is about 3 MPG lower than what my average would have been under the same driving conditions.... I can't help but attribute the loss in fuel mileage to the increase in volume of the fuel on the day that I filled up weeks before when the temperature was warmer.. Maybe I will get better from this tank ..... The differences in power output when the temperatures are low are amazing.... I wouldn't know this if I hadn't driven aggressively so forget about what I said about getting better mileage from this tank

 

I always fill up the same way everytime. I pump the gas and whatever it stops at, I round up to the nearest even dollar amount. This is the most consistent way of doing these types of tests, along with using the same grade and type of gas and even the same station if at all possible.

 

If you try to put to much in it goes back into their tanks after you pay for it.

 

I know I have put in the amount I have used by always filling to the top... Doing so is good for over 100 miles more distance that you would get by rounding off to the next dollar. I stop when my gauge said 1/4 and put 10.9 gallons in it.... As much as I love having an almost insane amount of power and speed I still miss the 37 to 39 MPG that I was getting so consistently..... I still beat my wife's Forester by 2 to 8 MPG almost all of the time though we have tied on a couple of occurrences when I didn't use my throttle controller in the ec5 setting and was wearing thick soled walking shoes.... I had to walk all over the VA hospital in my driving shoes and I was having bad pains in my legs from doing so.... I guess I need to keep some supportive walking shoes in the car and change out of my drivers if I am going to be standing around or walking.... I need to sleep, I am just too for off topic. See you fine people later.

 

Time for foooootballllll!

 

Here is some driving tips.http://static.webwarriortools.com.s3...iving-tips.pdf ,I agree with most of it but there is a difference in gas quality and between premium,regular.

 

SB - Like I say, it's all about technique. Interesting read even though we don't drive hybrids. Lot's of good points to consider. When I read something like this I tend to try and incorporate the style into my driving profile. What I'm learning about fuel trim and open/closed loop and engine load/throttle position and ECU's tells me it all falls back on how you drive.

Thing is all the tech info I'm sifting through relates to diagnosing problems - stuff a good mechanic wants to know - how to fix it. My quest is to try and find out how it works, then optimize how I work it.

Amazing how the industry has improved the way auto engines work but has been really lacking in informing the public as to how to drive them. Everything is aimed at the lowest common denominator. I'm sure many would see your last link as insulting and/or not important to them - good for little old ladies or grandpa... yea, that's nice now get out of my way and let me drive my car.

Choice of fuel has to make a difference. I'm not one to diddle around talking about other cars, I own a FIT and I'm now rather sure that the engine in my 2010 can and does take positive advantage of a high octane fuel. Now is that 'worth it' to me to use that fuel? That is really the question. I've lived long enough to realize that the way the world runs today is hardly 'worth it'. Otherwise out country wouldn't have a debt measured in the trillions and our States would not be on the brink of default. [must be the -10F I see right now and the fact that my house is making strange cold noises]

I'm seeing 36-37MPG on the OBC. I'll calculate a two tank average in about a week, all local driving. My issue is with the difference between the 'computed' and 'calculated' averages in MPG and understanding the effects of this cold weather on them.

With temps dropping like a stone as I type it will be interesting to see how the FIT starts in the sub-zero AM. Not sure of where you are, but I'm seeing over 24" of snow on the ground that hasn't even hinted at melting, though there is a 2" layer of ice embedded around 10" down.

 

I was not try to be insulting. The link is not for hybrids or I did not take it as that, they did compare it to them. As far a premium, if I got the mpg your getting I would use regular too, but gas is different all over the country and I see the results of premium here. I also drive a lot more than most about 10 hours a day between my truck and car. The Interstate around here if you drive 55 your going to die, so keeping up with the slowest driver in the second lane is how I drive. My wife uses regular and we have the same cars, so I see the problems with out using it in my car.

 

KC - Try -6F. May have to put the shorts away for the winter.

I suspect the .4 litre extra went in the filler neck. Anyways I now know about how far I can run once warning comes on.

 

I know you didn't mean it to be insulting. It's a great link, just that I don't encounter many drivers on the open road who seem to be getting it.

Back to the 'is it worth it' part. It has to be worth it. I certainly don't use the same computer I did 10yrs ago. I've learned to take advantage of the technology, though my cell phone is a 'no contract' pay-as-you-go 11cents a minute phone. I try to keep order in my life by not getting swept up in all the hoop-a-la big business would like me to.

I was a strong believer in regular fuels, unless your vehicle said other wise. Then I got a Cadillac. A 1996 Deville to be exact and it was rated for premium fuel. I found an excellent on-line forum and started understanding my ride and the NorthStar engine. I learned about knock sensors and that my car would perform perfectly well on regular fuel. did I run regular fuel, most of the time not. Some how, in my understanding, it would run better on its rated fuel and the 'motor heads' in the forum presented strong dyno evidence supporting that position.

What I was failing to see was the fact that my Cadillac would perform perfectly well based upon my driving style. To keep it smooth all that was needed was a monthly Full Throttle Acceleration. This is what kept me loving that ride, more fun than you really should be able to have ;-)

Well, I got rid of the Caddy and got my FIT because I was impressed with the economy and common sense it represented and a 14yrold car was catching up to me and not in a good way. I then came to this forum and continued my quest to 'understand' the FIT and its i-Vtech engine. Fuel use was something I assumed I knew about and 38MPG on regular was way better than 26MPG on premium. I learned about knock sensors in the FIT and listened to the proponents of reg vs prem fuel and learned a bit more about my Honda.

I'm now convinced that my FIT will positively respond to premium fuel. And that's not 'positively' in a definite way, but more a beneficial way. You, for one, have helped bring that understanding to me. The question remains, is it worth it...

That bring me back to the fuel supply/formulation issues in our great country. Regionally fuels vary. I'm not at all sure I understand how, but the empirical data suggests it. I also know that fuel from a 'high volume' station is preferred. I'm also sure that regular fuel sales far exceed sales of premium so, that leaves me, in my typical up-state rural/suburban driving world, with regular fuel being the best choice.

Now I also do a fair amount of turnpike driving in 6-8hr segments, though I'm no where close to your driving profile. Under those conditions I now prefer to fill up w/ premium. Notice it's my preference - FIT runs well w/ regular. I choose to run premium because it will provide a more efficient power curve and provide an bit better economy, in other words the FIT is engineered to take advantage of it.

All in all I really haven't changed my driving style over the years. What has happened is the cars we all drive have gotten decidedly better. I bought my 2010 FIT for much the same reason I bought my 1967 VW. I used to flog the crap out of the VW and every now and again I flog the FIT. Thing is the FIT is a whole lot more comfortable and a bunch more fun to flog_!!

 

I just found this thread after searching for a while about winter fuel economy...i apologize for bringing it back from the dead. I just recently drove from Ft Rucker, Al to overland park, ks. When i got into the colder weather about 700 miles into my trip i really notice a MPG difference. The temp when we started was about 55* and 0ft elevation, but on my last fill up between springfield, mo and overland park my avg MPG fell from 35.1 to 33.3. The only thing i can account for is the 25 degree temp shift as the sun went down and the northern climate was much cooler. Around KS we have had an average temp of about 30* with a high of no more than 42* and my gas mileage has gone from 29.1 city to about 26.8 city with a little highway. Im hoping the cold weather is what is making my MPG fall because my 2012 fit sport a/t only has 1300 miles on it and if the mileage continues to fall i will not be happy

 

Weather has a lot to do with mpg. Cold weather causes the ecu to enrich the fuel trims due to the fuel does not vaporize completely so more fuel is add to make sure there is enough fuel to burn for the power stroke. Gasoline is comprised of different hydrocarbons that vaporize at different temperatures. The fuel specifications is rated at 60 degrees and there is temp. corrections for temp, barometric pressure, engine temp, and winter fuel also has up to 6 percent less BTUs which add up to a 10-25 percent loss in normal driving depending on where you live. Then you have knock under high load which is another subject. My brother in law with a few thousand miles on a Nissan is complaining too. Not all gas is the same and its up to you to figure out what works best. Try higher octane and or different gas stations.

 

My economy for my 09 MT:37.5 summer, 35.5 winter, 34 winter with snow tires.

 

2009 MT Fit Sport. 29/30 MPG in the winter and 34/36 MPG in the summer, mostly city driving (70%).