2012 Civic MPG - share your current gas mileage

Since September I have averaged 25.90mpg (my own calc.) I have logged every fill up. I drive 75%/25% highway, city respectively. On the highway I typically drive 70-75mph with Cruise. In the city I typically shift around 3500-4500 rpm. I have also noticed that my fuel gauge has gradually decreased based on my past trips. Before, my last bar on my gauge would go off around 310-315 miles, today my last bar went off at 270 miles and reading 25.5 mph on the imid and I haven't driven any differently and have been using the same gas. Any thoughts on this? Even with my fuel gauge completely depleted, im going to continue to drive until I reach 300 miles on my trip to fill up. And I use the fuel monitor app on ios to track my fill ups

2013 civic si sedan
 
9 reasons why your winter fuel economy bites!

As if we really needed another reason to hate winter.

Those of us living in northern climes have already started to notice the seasonal decline in fuel economy, even with careful attention to sagging tire pressure (probably the best known effect of the mercury's slide).

Yet, despite diligent all-around maintenance and continued careful driving, cold weather fuel consumption can be dramatically worse than in warm temperatures.

How much worse?

Have a gander at these calculations for a Honda Civic hybrid at 60 MPH in varying ambient temperatures:

MPH-----AMBIENT-TEMP-----MPG (US)

60------------95----------52.98
60------------85----------52.62
60------------75----------51.16
60------------65----------49.12
60------------55----------47.22
60------------45----------44.67
60------------35----------43.05
60------------25----------41.54
60------------15----------39.41
60------------05----------38.09

Look at the extremes: the coldest MPG is 28% lower than the warmest.

My own experience supports this: 12.5% worse mileage during the colder half of the year (Oct 15 to Apr 15) than for the warmest half (Apr 15 - Oct 15), on average 2002-2004 in my 1989 Accord. Comparing just the warmest months (Jun-Aug) to the coldest (Dec-Feb), the difference is even more apparent - 21.2% worse (2002).

Why so bad? Off the top of my head, I could think of a couple of reasons to explain it, but together they didn't seem significant enough to account for the magnitude of the change. With this mystery to solve, I hit Google. And here's what I learned...

9 reasons your winter fuel economy bites

1. More idling

This should be a no-brainer, yet parked idling cars are a common sight in cold weather. Resist the temptation to idle your car to warm it up. An idling engine gets 0 mpg. Consider also that idling the engine does nothing to warm up the tires and drivetrain.

Even in the coldest weather, you can begin driving after 30 seconds from a cold start - keep speeds low/moderate and use gentle acceleration until the temperature gauge starts to climb.

2. Low tire pressure

Of course you're smart enough to keep up your tire pressure as the temperature drops, right? A 10-degree (F) change in ambient temperature equates to a 1 psi change in tire pressure. Fuel economy declines 0.4 percent for every 1 psi drop.

3. Increased rolling resistance

Even if you're completely attentive to proper tire pressure, cold ambient temperatures will still cause your tires to return worse mileage. That's because a tire's shape isn't completely round - the sidewall bulges out at the bottom, and where the tread meets the road the small contact patch is actually flat. As the tire rotates, it constantly deforms to this shape, and this deformation requires more energy when the rubber is cold and hard. Rolling resistance at 0 degrees F is 20% greater than at 80 degrees.

4. Crappy road conditions

It's increased rolling resistance of another kind: driving through slush and snow. And then there's its wasteful polar (no pun intended) opposite: no friction at all! (A.K.A. wheelspin on ice.)

5. Lower average engine temperature

In the winter, an engine takes longer to reach operating temperature and cools off faster when shut off. Since the engine management system orders up a richer mixture when cold (proportionately more fuel in the air/fuel combination), more fuel is being burned overall.

A block heater can offset this problem (improving fuel economy by 10% in sub-zero conditions), as can garage parking, and combining trips (to minimize the number of cold/hot cycles).

Also related...

6. Higher average lubricant viscosity

Engine oil thickens as it cools. So does transmission and differential fluids and even bearing grease. Significantly more energy is needed to overcome the added drag these cold lubricants cause.

Using synthetic fluids can address this problem, since their viscosity changes less at extreme temperatures than traditional mineral fluids.

7. Weaker gasoline

Gasoline doesn't vaporize readily at very cold temperatures. So oil companies formulate fuel differently for cold-weather markets in the winter. Unfortunately, the changes that provide better cold vaporization characteristics also result in less available energy for combustion. You won't get as far on a liter of winter gas as you will on a liter of summer gas.

8. Higher electrical loads

In colder temps, you use electrical accessories more often:

- lights (in higher lattitudes it's darker in the winter)
- rear window defroster (because it's easier than using the ice scraper, right?)
- heater blower motor (I don't have a/c, so this isn't balanced out during warm conditions); heated seats/mirrors
- windshield washer pump (because it's easier than using the ice scraper, right? And for frequently cleaning off dirty road spray.)

9. More aerodynamic drag

No, I'm not referring to the layer of snow you're too lazy to brush off the top of the car (though that would hurt mpg too).

A vehicle’s aerodynamic drag is proportional to air density, and the density increases as temperature drops. For every 10 degree F drop in temperature, aerodynamic drag increases by 2%.
 
troublemecca said:
13 si sedan... Ever since I got the car I've been getting terrible mileage... Average on most tanks is about 23mpg with a healthy combo of city and highway.... The best I've seen so far is about 27mpg...
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Im getting the same... but mines an LX. Which makes it even more pathetic.

Getting really frustrated with people throwin around high 30 numbers here when ive never even broken 30 since owning the car. 2500km here
 
I don't have any bolt ons and I would love to average about that much before I do acquire . I didn't buy the car to drive like my grandmother. But I'd like to see at least 30 mpg under normal driving conditions
 
Cbland13Si said:
I don't have any bolt ons and I would love to average about that much before I do acquire . I didn't buy the car to drive like my grandmother. But I'd like to see at least 30 mpg under normal driving conditions
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I am getting 28mpg with with full bolt-ons. The car sees VTEC at least once a day when the roads aren't slick.
 
My car see's VTEC multiple times a day. My next fuel up is gonna suck, lots of high revving, high speed going
 
Haha pretty much. It's all good though, That's how I was on my motorcycle too
 
If I shift before 3000rpm consistently, and go straight to 6th from 4th, and cruise at 75 on the hwy I consistently get 30mpg... its really boring though
 
I get as good or better gas mileage when I don't focus as much on shifting on or before 3k RPM, etc. I do usually skip 5th gear though, unless I need it.
 
wanga said:
We are getting 27.9 on our Si with mostly city driving. We're going up to PA this weekend, I'll reset and take some pictures for that trip, it's highway and then mountains/twisties.


Sent from my iPhone using Tapatalk
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With a K&N drop in/Intake Res Del/Exhaust Res Del I am getting 32.5 combined with city and highway in my Si! I drive downtown Houston every other day. Man I get better MPG at 80 than 65! It's crazy... But respectable for mostly city! We don't have hills here, have overpasses! HAHAHA
 
I also find that a lot of the time I get better mileage as I speed up while driving on the highway, while I have my trip computer pulled up, even without a K&N filter :-D
 
Figured I'd pass on some information. Data has been collected on every tank since April 2013.
2-22-14GasMileagevsSpeed_zpsfd10d0e4.png
 
For the sake of comparison below are my last two fuel-ups with Trip computer-view vs. Fuelly (manual calculation).

imageedit_15_6837613277_cropped.jpg

Off of Fuelly:
Last two fuel-ups @ Feb 25 2014.jpg
 
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Went for a little joy ride today, temps are finally starting to heat up. It was about 7C (45F) and I hit 5.8 L/100 Km(40.6mpg) with a mix of highway and country road (no street lights and very little stop signs). This was on winter tires so as it heats up and on summer tires i'm hoping for it improve. Pretty good for 5 speed with a highway Epa of 36mpg. My province is fairly hilly which can hurt your MPG. Can only imagine what I could get if I lived in the prairies.
 
Man the
Wytwolf said:
Went for a little joy ride today, temps are finally starting to heat up. It was about 7C (45F) and I hit 5.8 L/100 Km(40.6mpg) with a mix of highway and country road (no street lights and very little stop signs). This was on winter tires so as it heats up and on summer tires i'm hoping for it improve. Pretty good for 5 speed with a highway Epa of 36mpg. My province is fairly hilly which can hurt your MPG. Can only imagine what I could get if I lived in the prairies.
Click to expand...

Lx's get such good gas mileage! I only get about 31 or so in my si when I am not getting on it
 
First of all I wanted to say there is a wealth of great information to be read in this thread. I appreciate all the great info that has been given out. I will be doing my best to make sure my tire pressure stays on track. I just created my fuelly account. Although I have an automatic I still took away a large amount of great info from here.

I have been trying different ways to save fuel in my 2014 EX-L Coupe since I bought it last February (02/15/2014), but have not had much luck. Most my MPG's had been sitting in the 27~ish range and I had been gentile with the gas pedal as well as using Econ mode as much as possible. I finally took my car on a long distance road trip (Lake Forest, CA to San Francisco, CA & Back) and decided to use Econ mode either not at all or only during certain parts of the trip. I finally started to see an increase in my MPG (although there was less city driving on the way up & way down) I still was impressed with the newer figures. The history kind of tells the story (3rd was my drive up, 2nd was driving the city & heading out of SF, 3rd was the 101 Freeway + Pacific Coast Highway (Plenty of sharp turns, up hill, down hill and so on)) Even in the city where I had to push the engine real hard to climb a lot of the SF hills I was still able to come out with a respectable MPG (Econ mode was off the entire time in the city). On the way down from SF I had to continuously speed up / slow down / climb hills, but the car was able to hold a very respectable MPG).



I then refilled my car yesterday (Easter) & drove out to Riverside, CA to visit my Family (Lake Forest > Riverside Approx 55~ miles each way) Both on the way up & on the way down I hit heavy traffic. Even with poor traffic conditions and Econ Mode turned off I was able to pull off 38.2 MPG for the road trip. Although I was not using Fuelly at the time I hope these numbers would be decently accurate.

Trip up to Riverside & Back...



End result (MPG)

 
Does the 2014 civic have a bigger fuel tank? My car has never shown over 366 in range after a full fuel up
 
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