philliesfan11

Hey Everyone,
I have a 13 ex civic that has 35k on the odometer. Ever since I bought it back in February I've experienced poor gas milage ranging from 20-23 mpg city driving. I've used the on board computers range and manually calculating myself and the results are similar. I've checked the air filter and it was clean and I make sure the speedometer stays on green as opposed to blue and the eco mode is left on. I'm at a loss for why I am getting such terrible mpg and any help or suggestions would be appreciated.

TheShodan

iTrader: (14)

Tires being worn or not inflated properly
Spark plugs not being changed on a regular maintenance schedule using cheaper-grade fuel
Driving habits (Biggest reason)

philliesfan11

I know my tires are properly inflated i check them weekly. So what fuel do you recommend i run bc right now i use regular 87? Also when you say driving habits do you mean driving like an idiot speeding around or just heavy on the gas pedal?

TheShodan

iTrader: (14)

It's not just the inflation, it's the wear of the tyres themselves. If they have reached way past their intended mileage use, then this could also affect your fuel mileage

IF the car was intended for higher octane fuel, then yes, doing that will help, but the point of using better fuel is to resist knock, and not negatively effect the spark plugs. Since this is an EX, you don't really need 93 octane, but you more than likely need to change your spark plugs because older ones can lose spark (wasting fuel) even with 87 octane.

Pick your poison. Both have negating affects to your mileage.

What you have to understand is that it is the combination of these list items that hurt your fuel mileage. There is no one thing you can do. You need to check them ALL..

philliesfan11

No that makes perfect sense. I appreciate the advise, i never thought to check and replace the sparks.

nsxmatt

Spark plugs are iridium and don't need to be changed till 105k miles. If the engine was sending that much unburned fuel through the car would throw a code. Calculating fuel economy in the city is hard to do. 20-23 is not unheard of especially with a lot of time idling or short trips where the car is constantly having to warm up or not out of the warmup phase. Best way to check the fuel economy is to do a 30 mile hwy loop and take an accurate measurement. Fill the car completely up, drive 30 miles or more on the hwy. Fill back up at the same pump you filled up with and calculate the mileage. If it's within range your car is fine, it's just your city driving habits. I work for Honda and we have to perform fuel consumption tests weekly and in 14 years I've never had one with a customer complaint fail. It's always driving habits.

TheShodan

iTrader: (14)

Even if they are iridium-plugs, that mileage is only at optimal conditions. If he's running terrible fuel, it could easily render Iridiums less-efficient due to the lower spark. Do that enough times, and yes, you're changing them more often, regardless of company or type.
But the rest of what you're stating is perfectly fine. I'm not saying these changes will make it over 40mpg, but that he'd run much more efficiently if these things were simply changed versus just asking questions all day and speculating. CHECK THE PLUGS. It's not difficult regardless of 105,000 mile intervals. (Which I've never followed anyway. If I had, my TSX mileage would have been **** years ago, before reaching 185,000miles. )

nsxmatt

It's an iridium plug, there is nothing to check. There is no traditional electrode to get dirty or foul. Changing out 4 $20 plugs just because is a horrible idea. I have 129k miles on the ones currently in mu 09 civic and fuel economy is the same as day one. There are literally millions of civics and accords running the same plugs and every single Honda dealer will tell you to run them till the factory tells you to. You are wasting money to change them at 35k plain and simple.

Jimmy six

My wife got 22 in her 2000 ex automatic stop and go. Market, gym, Doctor, etc. She gets 24 on her 2015 LX auto same driving. Wnen I drive it city style I get 25-26. On the road with the ECO turn on we got 42 mpg on a 700 mile trip. It's how you grove for the most part. My 2003 HX 5-speed gets 33-34 in town now but got 37-38 when new. I blame the fuel for some of it.... Good luck....

TheShodan

iTrader: (14)

That's fine. As long as the OP is aware of his options. I've never felt that anything as simple as checking to confirm was ever wrong. Especially with an engine as simple as this.
Perhaps we're simply at a point where I think we can simply agree to disagree on procedure of DDXing. There many ways to "skin a cat". Is that ok?

nsxmatt

I agree, everyone has different opinions on the subject. At lest the OP has heard from both sides so he knows the pros and cons of each.

foumer

I get around 26 mpg on my 07 civic with 146k miles around town. No lead foot here, I drive like an old lady. I also use the cheapest 87 octane gas too. On stop and go traffic I see people racing to the next light or stop sign and wonder why their mpg is horrible.