iHaveProblemz

I've been monitoring how many miles each fill up I can get up to and I've noticed each time that the highest I can get is about <300 miles on a 13.5g tank. It's a fairly new car; 2007 lx. Only difference is I have a catback exhaust. I use to think it was just the way I was driving but as I've been carefully monitoring I will not allow my car to go above 2-2.5 rpms unless of course uphill. I always start slow, never a jerky start, and usually I'm really good about keeping my car at a constant 2000 rpms atleast citywise on flat land. I've tried to research it and I've come across exhaust leaks and other things but I wanted to get an opinion. Any help would be appreciated!

sdaidoji

iTrader: (1)

the trick is how much you can keep the throttle off while maintaining momentum. i am pretty much hard on getting to speed but then i keep the car rolling.
going slow or keeping below certain RPM does not do the trick.
when you let foot off the throttle and engine is above certain amount of rpm (like in a downhill), FI will shut off - zero fuel going in, until you press pedal again.
I don't brake in corners, most corners can be taken faster than the posted limit (that is what i mean by keeping the momentum). off course you would need to learn how to corner well and safely with only throttle work and suspension setup, though :P

iHaveProblemz

I understand what you're saying, but the thing is I do coast to stop lights, stop signs and don't use the gas unless needed. I can take a turn going 20 mph as long as I coast easily without my tires squealing. I got new tires and they are amazing! Trust me I don't gas it whenever I want and tailgate like my girlfriend (she'd be pissed if she knew I said that ). My car is my everyday ride though and going to school does have a steep hill that's a must every Monday-Thursday. Now I have had start up problems in the passed and since I've been researching it, I've heard new spark plugs. So I wanna test this out since spark plugs are pretty cheap. I'll just install new ones and see if I notice anything, but I wanted to see if anyone else had this problem or had a general idea on what this might be? I'm only getting about 21-23mpg.

capacivic

If you're only getting 23mpg then something is wrong. Have a Honda mechanic check it out.

Also, gasoline with ethanol will reduce your fuel economy a bit.

altua

I have a Honda civic 2010 EX-L and mileage I get has not crossed 28MPG in a while.
I drive 32 miles daily, out of which 4 miles are in city. I used to get 32~34 MPG earlier but since I change my tiers to Bridgestone Turanza with serinity mileage has been dropping. I have even set the tire pressure to 33 psi cold. I use full synthetic oil since I go on long drives from time to time and only use Honda oil.
I mostly use gas from Shell or Chevron or 76, only now have i started going to Costco since it doesn't seem to be making any difference to the mileage.
I am almost at 36k miles.
Anyone has any thought as to what can be causing this drop? I drive mostly 65~70 MPH and rarely to never do crazy acceleration.
Only thing in the car except me is the spare tire and a few bottles of drinking water.

Matt_75

You mean semi-synthetic or synthetic blend right? I'm about 100% sure Honda doesn't use a full synthetic in North America at least.

altua

Full Synthetic. My civic came with synthetic blend. I checked the bottles, they say full synthetic.

Matt_75

Really? Can you direct to a link that sells Honda full synthetic oil?

EDIT: Never mind. I found it. I guess I just didn't know.

TiggerDX

iTrader: (1)

Are you running out of gas each trip? if not, you have no idea of the mileage you are getting. You need to set you trip meter to 0 or note the current mileage when you fill the car. Then note the mileage when you fill up the next tank. Then divide the actual miles driven by gallons used. Do that over 3 or 4 tanks then you will have an average of what your actual mileage is.
The way you are doing it, you could easily be off by 5 to 10 mpg. Then you will know if you are getting much less than you should be.

iHaveProblemz

I don't run out ever, I will go until my car has no bars of gas lef, fill up. And I don't ever divide the gas by the full tank. If I'm about to run out completely of gas, I usually just divide by 13. I always calculate my miles I drove during that fill up and I check how much gas gets filled up into my tank each time.

ezone

You have math problems.

dubtee1480

Take your miles from your trip/ODO and divide them by the gallons you put in your tank from the receipt/pump read out. If you divide by 13 every time you aren't going to get consistent readings. You can log them here to keep track of them and get a long term average: http://www.fuelly.com/

capacivic

My '02 Civic had a 13-gallon tank. But when I ran the tank down to well below "E" and filled it up, it would only take 11-something gallons of fuel. Assuming you're burning all 13 gallons between fill-ups is not likely. It's probably 11 or perhaps 12 gallons.

danwat12345

MPG Miles Per gallon miles/gallon EX: 400/10=40.00MPG

Do the math so you can be accurate.
If your MPG really is at 23MPG then hook up a thing to the OBD2 port and look at air/fuel ratios or something.

dubtee1480

Ultragauge.... watch the A/F ratios, trouble codes and watch mpg

**edit**
I didn't intend to quote, wasn't paying attention