I don't know about the computer but it says I'm getting 40 city and 44 highway.

So I'm pretty impressed with the fuel. Consumption coming for a ram that gave me 12mpg. And the gasoline in my country is 4 dollars a galon it makes a lot of difference.

It is the manual transmission I wonder how much it will consume in the cvt.

And yes I drive slow but I don't care. The slower I go the richer I get(or the less poorer).

 

Ok, since I keep the details of all my tank fills on a spreadsheet, just for kicks and giggles I did an analysis of my last 6 fillups and arrived at the following:

1. mpg per Fit dash gauge is on average 3.94% higher than actual calculation
2. mpg per Fit dash gauge is on average 2.21 mpg higher than actual calculation

 

It's best to keep thinking in terms of percentage difference. When you're getting low mileage, X% error will be close to real mpg- but when you're getting better mileage the same percentage of error will be farther off from your actual mpg.

 

Hiitting 41-44 mpg consistently going to school everyday.

10% city 90% highway.

15 EX

Very sastified FIT owner.

 

EX-L Nav CVT getting around 33-35 in town...41 highway...38.5 average these last 500 miles. 1,400 miles on the car.

 

and what method may that be? I want to know please!

 

The best I am getting in the city with a ton of stop lights and traffic is 30 mpg and thats trying really hard. So Cal traffic sucks.

Evon mode on as well

 

30mpg in those conditions is very good. And it will make you look even more forward to anytime you can get out on the open road to see the really good numbers.

 

Same here but 35 mpg. Lots of short trips at 16 mpg, 30% stopped at lights. I just think how awful it would be in something else.

 

So my car tells me I hit 35 mpg on a 52 mile trip.

When I divided miles by gallons I got 47 mpg, but then I decided to top off my tank and got 34 mpg.

Whats right and whats wrong?

Before the top off gallons of gas bought was 1.1, then after the top off it was 1.5.

 

I would go by the top off number so 34MPG.

The most accurate way to do it is to completly fill the tank and start your miles at zero. When you want to calcate MPG completly fill your tank and divide by the miles that you have driven.

 

Yea that is exactly what I did.

thanks

 

If you use the Fuelly - Track and Compare your MPG site like many people on here do, you will get an average running mpg, last tank and other data. I had my first fill up on my new Fit last week and I will try to do it when the dash displays range of 0 miles. When it is at 0 you still have about a gallon left in the tank and that gives you enough to get to a gas station and you will have consistent readings without putting yourself in a situation where you run out of fuel.

 

The way I do it is fill up at the same station, and same pump, and when the pump stops on its own, not continuing as some do to fill up to the brim.

 

For that short of a trip (singular), the error in different stopping points when pumping gas is much greater than any error in the car's computer figuring mpg. The car is probably the closest.

Over the long term, accumulating gallons filled and miles driven for successive tanks, you can get a more accurate number by hand. Most people seem to find that the car's meter is within a few percent of reality, often reading slightly optimistic on average.

 

the problem with hand calculations is being sure you refilled your tank to the exact same level as before you 'zeroed' the odometer. like most cars, its extremely difficult simply because you have no real indication of the gas level.
the only way we do it is by weight, before and after with no change in the contents of the car. most of the time we come within 2-3% of the computer mpg which is measured by the accumulation of gas throughput of the ecu. If you need more accuracy than +/- 2% then weigh accurately. and yes we take a measured sample to check the lb per gallon. time consuming but accurate beyond hand calculation.
oh, and don't expect to get much accuracy on any refill less than 5 gallons.
and if you think refilling to overflow you really screw up; the poor fuel system has a problem with the vapor trap system. it can't figure out what is going on and where to let the gas go to. won't help your driving either.

 

There is no practical way to calculate MPG for a single tank. Given the convoluted plumbing and flat tank the amount of fuel you can get into the tank varies depending upon the position of the car. Tilt it a bit one way and you can get a bit more fuel in. Tilt it the other and get a bit less.

The odometer in most cars is a bit pessimistic, reading a couple of percent low. The reason for this is to eliminate claims of optimistic odometers ending warranties early.

So, how do you get accurate MPG figures? First you have to calibrate your odometer. This is easy with a GPS unit that records miles traveled. Drive 50 miles according to the GPS, then divide the 50 by the distance shown on the odometer. This gives you the correction factor by which you multiply the odometer figure to get the true distance traveled.

Next, you have to keep track of both the true mileage traveled and the gallons dispensed over several tanks. This caused the variations in fill to be averaged out. After 10 tanks you should be able to get a fairly decent figure.

The on-board MPG reading is simply an estimate. The car does not have a totalizer to measure fuel used, so it simply uses the sum of the injector opening times. This is used to estimate the amount of fuel that passed the injectors which when combined with the distance traveled yields the MPG. Since both fuel used and distance traveled have built in errors the number will not be very accurate.

 

I began using fully but I quit. I am not a really tidy person and always forgot or was to lazy to upload my miles in every gas refuel. I just trust the computer. It is pretty accurate with a 10% difference. But still not much difference.
Also in my country fuel station steals you and they never deliver a complete gallon so it depends where you charge in some they steal more than in others. so i think, it will be useless in my situation.

 

My hand calculations (over 20K + miles so far) read about 2-3 MPG lower than the car's number (I've left Trip B untouched since taking delivery). The app I use to record fuel purchases also tends to read a little high (it shouldn't, so they're doing something funky in their calculations).

es

 

cars oday have pretty accuate odometers and speedometers thanks to todays enforcement and legal issues, including leasing. 2% is typical.
likewise your gps isn't more accurate than 2% either. ask google.
averaging mpg over several tanks will be useful only if you fill to an approximation of the same level. deviate much and the average is changed.
like manufacturers, running preciely known distances and refilling to the same vehicle weight with precisely known gas specific gravity is the only way to get at least 1% accuracy.
and btw, totalizing the injection rate signals is probably better than any tank refilling by gallons.