I have tried regular and midgrade mpg drop to 32 mpg, The highway just open up 4 lane both directions so i will let you know if it goes up or down the best I got was 42 mpg 2 tanks early summer. (Chicago) Commute is 2 mile stop and go to highway was 24 mile stop and go construction highway and 3 miles to work stop and go w/ train delays. There is a lot more power with premium, could be in 5 gear at 35 mph and dont need to down shift during acceration. I know some of is driving techique but when your engine has more power you dont have press on gas as much and your car does adjust for different fuels. I will continue to use premium, if regular wasnt so water down with ethanol I would use it. I know premium gets about a 10 percent increase in mileage over regular from years of experience.

 

That's 19% (difference between 32mpg and 38mpg). At least get your numbers consistent.

 

The best was 20 percent. So you problably change your oil every 3000 too.

 

Don't confuse SilverBullet with facts!

 

I have a feeling that the drop to 32 had other factors. Do you have a History of your fill-ups? (curious to see if there were potentially other factors involved). Just for the record, this is calculated mileage?

My range is in my sig (well.. the avg and best tank) My low so far has been just below 32mpg and all of my numbers seem to jive with yours except for one major factor; the octane rating (ok.. 2.. and the cost of gas - that's a number ). My Fluctuation has been based upon Temperature and Car warm-up alone.

I don't personally see how the gas could give you that big of a difference since amount of energy given off by any octane level of gas is the same. I had to use a few tanks of Regular in My GS-R and my fuel economy never dropped although I did lose a little power. Octane is the resistance to explosion which allows for an engine to have a higher compression ratio (which in turn means a more powerful engine). Engines can Retard or advance timing automatically but they cannot increase the compression past their max (in this case 10.4:1) which means if an engine is igniting the gas at the point of max compression, it is at it's max power. Adding premium fuel to an engine igniting at max compression will do nothing but If the engine [running on 87] is retarding the timing a little bit because of the lower octane rating, you will see a minor increase in power [with the addition of 91]. I doubt any engine hits the max compression on a lower octane fuel but these engines are designed to come close... REAL CLOSE! The L15 might advance timing a tiny bit [to get the compression closer to it's max of 10.4] with a higher octane engine but not enough to produce anything really noticable. If there is a noticeable gain, I'd say there's a problem with the engine.

Upon what I've read throughout this post and based upon my own experiences using Different grades of Gas in Honda 4Cyl's (B20A1, B18A1, B18C1, D16Y8, D16A6, L15A) over the last 15 years, I've never seen any change in economy that I could attest to being Octane Related. Temperature, Driving style, Driving conditions all have shown different economy ratings but I've never seen a change that i could honestly attribute to be in octane related.

Granted, these are just my experiences and not scientific facts but 9 years of my driving life was spent in NJ (NYC suburbs) and the last 6 in Rural VT (1 yr in North Central PA). Also not trying to say outright that Silver is wrong but I'm just trying to wrap my head around how/why such a drastic difference might be obtained.

There's always the possibility that Honda has just told people to use Regular because the fit is an Economy car but I would have expected to see something in the manual that states the car runs fine on Regular but you will obtain higher performance with Premium.

We'll see what the CRZ recommends as I believe it is coming with a variant of the L15.

~SB

 

The only way I can imagine premium having a significant difference in MPG in a Fit would be if it had no ethanol, since ethanol has a lower energy density than the hydrocarbon components of gasoline. Unfortunately, most gasoline retailers don't tell us the amount of ethanol in their fuels, but since ethanol has a high octane rating (113), I would expect premium to have more ethanol, not less, than regular, and here is a retailer who states exactly that: Ethanol, octane and engine performance . That said, in most states, I believe a 10% ethanol blend is mandatory for any grade, at least in winter.

In the past five years, I can recall seeing only one gas station (somewhere in Kentucky) that advertised their fuels as being alcohol-free.

 

I believe ours say "up to 10% ethanol" on all of the pumps We've got one station here that has none and they charge a "Premium" (Pun intended) for it.

~SB

 

My mpg for first two fill ups, 29.6 and 29.3. 2010 sport at with nav. Daily commute is about 20 miles each way with 50% highway and 50% city and country back roads. We are driving very lightfooted and upshifting early as much as possible. Love the car so far but wish I was getting mpg's like most posts I've read.

 

Are you sure you got a complet fill-up each time? Mine got 38mpg from the start. It is hard to get a consitent fill-up to get good calculations with the Fit.

 

try shifting between 3-4k rpms on hilly terrain

 

Filled-up till pump stopped with both fill ups. Calculated, by the way.

 

i just finished my second tank. i went from just under 41mpg on my first tank (90% highway) to 31mpg this tank (80% city).

i love driving the little thing but it seems like it might be some serious work to keep the mileage up.

on a positive note, the turning radius is so good for downtown u-turns.

 

I must digress (and go offtopic!) The turning radius of my 2nd Gen CR-V is *much* better than the Fit's!!!

 

heh heh, well that must pretty good then.

 

Good point. This illustrates the need to calculate fuel consumption based only on the amount of fuel registered on the pump rather than on knowledge of your car's tank capacity. I wonder how many people are doing this wrong.

If you fill your tank only to the point where the pump clicks off and then assume you have exactly 10.5 U.S. gallons in the tank you're already off the mark because some pumps that pump at a slower rate will allow you to put more fuel in before clicking. (Possibly because faster pumps create more turbulence in the tank and click off prematurely?)

I've carefully filled my '09 Sport MT to the brim (not recommended under normal circumstances) just to see how much range I could get by filling up the rather long filler neck. The difference between doing this vs. filling only until the first click was over $5 (Canadian prices of around $1 per liter and Canadian funds) and almost 60 miles extra range at 70 mph.

So the only way to calculate actual highway miles per gallon is to first drive for at least 15 minutes to insure engine operating temp is well into range, then fill the tank to the brim, then driving at a constant highway speed for at least an hour. Now re-fill the tank to the brim again and take note of exactly how much fuel was metered by the pump. From there it's a simple matter of doing the math.

 

I looked it up, actually not that different. CR-V has a short advantage on turn radius, but I guess since it is so much larger than the Fit, it *feels* like a tighter turn. It's awesome really.

2002 CR-V turning curb-to-curb: 34.2 feet
2009 Fit turning curb-to-curb: 34.4 feet

 

Come on, people, I know how to calculate mpg. And this suggestion is just ridiculous. I'm not a rocket scientist, but i have been figuring mpg for 20 years. My old crx got 45 mpg pretty consistently. The fit numbers I have posted are using same station and same pump. Also the numbers are close to the gauge numbers. Bottom line is I am getting what the EPA numbers are. I have not gone over 3000 rpm yet. Although I just hit 600 on the odometer, so I will soon be seeing what this baby can really do.

 

Try and have patience when others are trying to help you out. I guarantee the reason your mileage is so low is you're bogging down because you're afraid to rev the thing. On hills, especially, you should expect to be shifting around 4k rpm.

 

This is mostly for future 2010 Fit owners looking for real world data.

On my '09 AT Sport my average city MPG is about 22-24. Highway is about 32-34. I live in a major metropolis and most of my trips in the city are short (1-8 miles). The highway miles were calculated from a 600 and 400 mile trip.

I'm a little heavy on the gas pedal so I would like to believe the MPG I'm getting is a worst case scenario.

 

Thanks for the advice on both points. Will try to be more patient. Also will try winding up the engine a bit. That'll be more fun too. Weee!