Supra-holic

+1 on air filter, I've been robbed of MPGs with a dirty filter.

niptek

i get 17-20mpg mix 50/50 on my 06 with 15k mileage stock. driving with window down or top down could lower ur mpg.

i use gas cubby iphone app to calculate my mpg

llckll

http://www.amazon.com/gp/aw/d.html?pd=1&a=B00336S7KS

You can try this as well if you have an iPhone.

ahrmike

Hows traffic around where you drive? I am 50/50 with stop& go traffic on both the highway and the streets. My car is at 76K miles

chuhsi

winter gas?

abechien

Thanks to everyone for your advice and responses! To answer some of the questions asked:
1. I make several short trips in general, so that could be the issue.
2. Recently we've had a mildly cold spell in Los Angeles, so a combination of the engine not quite warming up enough and the winter gasoline could be causing this.
3. I am running on Yokohama S. Drives now...they have decent tread left and they're summer tires, but works fine here in CA.
4. Terrain here is mostly flat.

From what I can tell, essentially a combination of cold weather, winter gas, and the like are making my gas mileage drop mildly. I will try changing my air filter and maybe go with an fipk (although it really doesn't look that dirty) and use fuel injector cleaner to see if that makes a difference. Again, thanks for all your advice!

whiteflash

I could be wrong but I know that California doesn't change its Ethanol blends. I'm pretty sure actually California runs a year round blend, unlike many other states for all gas. Not 100% Sure on that though. Cold starts, and short trips will definitely do that. All in all your mpg is kinda at the bottom of the spectrum, but it's not out of it. Goodluck

H22toF20

The worst I've ever gotten is 25.5mpg mixed driving and I usually average 26-27mpg. How is your driving style? I shift no later than 3k, usually 2.5k after 2nd gear; I'm usually in 6th gear at 35mph assuming I'm not accelerating. Another trick is to be light on the gas pedal. I usually have some VTEC pulls mixed in to that as well. Who wouldn't? It should also be noted that Oregon puts up to 10% ethanol.

But really 17mpg seems really low. Ether you have a very horrible driving style or something isn't right with the motor or driveterain losses. I had a VERY dirty filter when I bought my ap1, I replaced it with an FIKP and noticed ZERO fuel economy increase. I did however notice a nice .5-1mpg increase with my HKS 75mm exhaust.

I think something is causing you to run rich. Check the plugs, MAP sensor, basic maintenance ect.

Bror Jace

+1 check for a sticky brake caliper ... after a 10-15 minute drive, one of the wheels will be smoking, smelling or otherwise show that it is overheated.

slalom44

If your defroster or A/C is on, this will take a small hit but not as much as top down or windows down. Be sure to minimize the amount of time you idle your engine. Warming up the engine is unnecessary.

If you spend a lot of time in heavy traffic, try not to ride too close to the car in front of you. Pressing the brakes a lot means you have to accelerate a lot.

I shift at around 4000 RPM as well, and I believe that's a good sweet spot for this car. I get great gas mileage (average over 30 MPG) however I admittedly do mostly highway driving.

The more ethanol in the fuel, the worse the fuel economy.

Consider using a 0W-30 motor oil. It will help your fuel economy during cold starts, along with many other benefits. I use Amsoil SSO.