Does anyone (else) use cruise control for better MPG, and I mean in everyday driving situations, not just the highway? I just started using it on my local commute (manual '15). Not sure of the results yet, but I'm left to wonder if it helps because cruize insists upon maintaining speed obviously on small hills whereas without cruize I can back off the pedal until I crest the hill.

 

So-so. It's great on level roads, but not so good going uphill. I disengage it and control the speed myself. Going downhill, I also disengage it and take my foot off the gas.

 

My sister-in-law has owned them since the beginning (8 different new models) and says that every year the gas milage would go down. I think it's because as she's gotten older she just wines (sp) the piss out of it more, ie shifting close to redline everytime. She hates the last Fit model with the collision avoidance feature as she drives on backroads in the winter when snow ladened low hanging tree branches automatically turn on the brakes.

My 2009 says I'm getting 43mpg, but actual is usually around 39.6mpg

 

As temperatures rise from the winter, mpg goes up.

 

Can anyone guess what's going on with my gas mileage? I'm at 110,000 miles and the lifetime average gas mileage for the vehicle has been 40 MPG but the last few thousand miles have been 36 MPG. I moved back to California from Utah three months ago. I changed the spark plugs at 100k (Ruthenium). I got a valve adjustment a few hundred miles ago but it didn't seem to change anything. The auto shop overfilled the oil so I had to siphon some out, which helped make it feel less sluggish, but MPG still isn't as it originally was. Any thoughts?

 

To Gekison with the major mileage drop. those are some serious changes in your Fit, but the worst might be overfilling the oil. I make the dealer come out before we leave the lot and check the oil level, and also make sure the % number is set back to 100%.
I am on my second Honda Fit, since 2008 and now a 2019 auto. I always calculate my mileage using a spreadsheet, although I like the numbers on the dash. My mileage average over the last 5 years is 43.5, But I often get 45 mpg on certain drives at 55 mph.
I recommend to you to run your tires at 38 psi, or even 40. The ride is a bit harder, but the mileage is much better. Some guys on here run there tires at 60 psi, and that is legal. But I would never go there.

As you know, dealers might be the 'experts', but they make a lot of mistakes.

 

Has the MAF sensor ever been cleaned?

 

I use Cruise Control for 90% of my driving. We do mostly highway driving. I agree about going up a hill, I always cancel cruise on those occasions.

 

I have a 2015 at almost 184k - 6 speed. Sub 120k I did an intake valve clean, chirped tires in 2nd and 3rd within certain contingencies after, noticeably better gas mileage and power. I popped off the intake mani recently and it's about due again. Also noticed highway mileage before 1st clean was maybe 36 when babying it, got as high as 45 directly after. Check your fuel trims, keep the valves adjusted, make sure your gearbox oil is squared away, alignment good, and intake valves clean (good PCV valve helps too) and you should be alright. These cars are a bit higher maintenance than some other vehicles but long as you stay on top, it will reward you.

Side note: I'm looking at adding some sort of intake manifold runner injection system to prevent me from having to consistently walnut blast the intake valves. Messy job. Would be a good idea if you're looking to keep things long term.

Also, for those using cruise control. The very purpose of cruise control is speed maintenance not MPG maximization. It takes less gas to power down a hill than up one. Inertia is your friend, use it.

 

I just joined this forum. So still seeing what's here. I like this thread. I made Post #1 today in the wheels/tires section. Looking to go to smaller wheels, maybe one of you will offer a comment there.

New to the Fit (just bought a 2017 EX) but not to MPG. I own a '92 Civic VX, which as some of you will know was EPA rated (later revised down) 48/55 mpg. With 250k miles on the original untouched engine, it still delivers 35-40 mpg in city driving (at minimum 4700 ft ASL, depending on ambient temperature and seasonal gas formulation).

When figuring your "true" mileage vs what the vehicle displays, consider some important points:

You need to calibrate your odometer. Believe it or not, Google Maps is a very good standard to check against. When it says X miles from point A to point B on a highway, it's very accurate, the longer the stretch the better. Another way to check your odometer is to cruise on a good straight(ish) stretch of major Interstate, and watch your odometer ticking along against the green mile markers flying by. It's good to have a passenger to help, with a notepad, but I've done this for hours on end by myself without crashing a vehicle. Either way you should come up with an error, like plus or minus 2%. If you buy new tires, recalibrate the odometer, as your tire circumference (and revs per mile) just changed! By the same token, always run your tires at the proper pressure.

Another issue is the gas pump. Let the pump stop your fill, don't try to cheat and add more fuel into the filler pipe, you'll introduce variation. The sensitivity of the shutoff-when-full feature varies from pump to pump. So if possible drive a round trip and top off both times at the same pump, and also park your vehicle on the same side of that pump, same orientation, to avoid having a different tilt to your vehicle. The deck is seldom truly level at a station, and it affects how much gas the pump will deliver before shutoff.
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Very good points. However I have a fifferent view to the tank filling. Fuel pump cutoff in practice is far from consistent even in the same pump and same car. E.g. slight change in nozzle angle and position will affect the cutoff. Therefore filling the tank so full that you can see the fuel level in filler pipe is the best way to reduce variation. Assuming the car is at the same lean angle.

In the long run this of course becomes insignificant, because only total volume and distance matters. Noting the odometer error of course.

 

I take your point, TnTkr. But I wedge the nozzle in the same distance, to where it holds itself in place, and the angle changes very little. I agree a visual is bound to more consistent, but on modern vehicles it could damage the emission control system, depending on the vehicle. And, particularly on high-mileage vehicles, there can be a leak that far up the filler pipe, which would otherwise be insignificant, and which could present a fire hazard. I'm not a nervous nellie, but I did find this on a AAA web page:

By topping off your gas tank even once, you begin to run the risk having liquid fuel slosh and flow into the delicate charcoal filters in these vapor recovery systems. Once they become saturated in liquid fuel, their capacity to capture and burn vapors successfully can be reduced or ruined completely. Not only do saturated filters in the EVAP and ORVR systems make your vehicle emit more hazardous emissions, but they can impact engine performance and reduce fuel economy. Eventually, these saturated filters may even lead to a “check engine” light or costly repair that was completely avoidable.
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That's right, there are such warnings, and I'm not blaming anyone to do as instructed. Personally I always fill the tank until fuel is visible (except rental cars), and have never had any problems. And never met anyone, who would have had any problems due to filling the tank up to the neck.

 

So I did valve adjustment, cleaned MAF sensor, oil change--brought 3.5 quarts to the mechanic, did a CVT fluid change. My fuel mileage is still 3-4 mpg lower on average than it used to be. Maybe it's carbon deposits like one guy said.
I don't know why it would be all of a sudden instead of gradually. It all started on my move BACK from Utah to Southern California and has stuck since. I used to live in So Cal and had great gas mileage.
Mechanic has said he saw carbon buildup in the back of the intake valves. It was a notable amount but nothing extreme.

 

Recently picked up a 2017 Fit EX with a 6 Speed Manual. I have a 60 mile commute to work and back and on my second tank now. 249 miles in now on this tank and averaging 50mpg via the Lie-o-meter. Last tanks calculation showed the meter to be about 2 mpg high, will check again on this next fill up.



Hodakaguy

 

Not bad! I get over 50 driving into town and mid 40s coming home. Hills make a difference. 😋

 

So far I haven't managed to keep my in town figures as high as my open road mileage....I'll keep working on it though

 

So do headwinds and altitude.
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The lie-o-meter maths out almost perfectly in this case.

Filling up from 0mi range I squeeze 9 gallons in. 9x50=450
450/2=225
The supposed tank size is 10.6 gal and an additional 25mi on your TripO is a half gallon which still leaves you right around half a tank.

That much better than my 36.4 average in the hills and valleys of New England lol

 

In 10 years of Fit ownership, 114k miles:
Average MPG 40.558
Average Fuel Cost $18.35
Average Per Gallon $2.264
Total spent $6,368.41

Parked Fit