Well, I am a relatively new Fit owner, I just got my 07 automatic base model last October. Like a lot of people, the advertised MPG was one of the things that drew me to the Fit.

But ever since I drove it back home, I noticed that I was getting nowhere near the mileage I was supposed to. Then, in November of last year, I went on a road trip and got about 230 miles from a full tank before I had to refuel. That translates to roughly 23 MPG, right? Keep in mind this was highway only. A test with mostly city driving got about 175 miles.

I've been changing the oil regularly, the tires are properly inflated, I checked the spark plugs just about a week ago and they're good, and I don't drive particularly hard.

I'm doing one more MPG test right now, and I'm currently at about 1/2 tank after about 130 miles. This doesn't look like it's going to end up any better.

Any help is greatly appreciated!

 

Start by actually calculating your mpg, not just guessing based on where the needle is. I can be getting near 35mpg, and still only be getting 250ish miles by the time the needle reaches empty.

If there is actually a problem, how about the air filter - when's the last time it was changed?

 

Yea that...

And maybe you need to straight up romp on it for a while.

Surprisingly enough mine does better on tanks where I have mixed driving including a few romps!

 

might have to undo the parking brakes to get decent mpg... jk. im going to guess and say you have a bad case of lead foot or you need to go to the dealer to solve a serious issue.

i dont think the air filter will drop mpg that bad, it might be a problematic tranny, clogged injectors, too many variables to just tell you its THIS one thing.

i own the more gas guzzling GE with 5AT and i get 35mpg avg and all hwy will yield like almost 40mpg, so 250mi per tank sounds like your fit is in need of careful inspection.

 

The first few numbers were calculated from running all the way through the tank. And the air filter was changed along with the oil just about a week ago.

I really don't drive it that hard. Only time I push it is when I merge onto the highway. I'm starting to think that it is some serious issue. Will I be covered by the warranty if it is?

 

i hope youre still covered under warranty. you said you bought the car in oct 2007 so you still have some time left on your 3yr warranty the thing is, are you past your 36,000 mile?

if you are under 36,000 miles youll have no problems getting it checked out at the dealership.

 

drive your car hard for a tank. if your car stays at a low rpm all the time, there can be a buildup of junk or whatever on your valves, fuel injectors, etc. running it hard will force more fuel and air in and clear it out. i had a similar problem.

 

Uh how often do you drive this thing? You said November of last year was the last "road trip"... is this your daily driver? If fuel sits in the tank long enough it does go bad. Also you need to take this thing on the highway once or twice a week and get it up to speed for 5-10 minutes or so.

 

Actually I bought it used last October (10/09), sorry about the misunderstanding. And I might be in some trouble then, because I'm at 52,000 miles.

Yeah, this is my daily driver. It gets driven A LOT. By "last road trip" I meant a long interstate trip.

Old gas is definitely not an issue; I'm having to fill my Fit up twice a week and it is killing me.

 

You drove the car until you ran out of gas?

Just do a quick calculation on your next fill-up, and get an actual mpg number. The dealer is going to need to know the same thing - if you tell them you're getting bad mileage based on fuzzy "per tank" figures, they're going to be skeptical. Provide documentation of trip clock readings and gas receipts, they'll take you a lot more seriously. And they'll also have data they can submit to HoA if it's not something specifically covered under warranty.

 

I'm assuming no check engine light?

 

I drove it until the fuel light came on, and then proceeded to put 9.something gallons into the tank. This was approximately 230 miles after filling it all the way up.

I recorded my odometer reading at my last fill-up as well as the exact amount of gas I put into the tank. And I reset the trip odometer as well, for good measure. Once I go through the tank, I will have exact numbers.

Nope.

 

See if you can get a good mechanic to check your car for all the possible culprits from spark plugs to fuel lines to sticky brakes etc. Honda dealerships aren't going to check anything unless there is a CEL.

Have you tried resetting the ECU and letting it re-learn? I'd also try running a bottle of Regane fuel system cleaner (clear bottle w/ yellow liquid) and going for a hard drive.

 

They won't check it unless the light is on? Well that's discouraging. I don't know if I can afford paying a mechanic.

I have not tried resetting the computer, nor do I know anything about doing that. But I am open to trying anything to get the mileage I need. So if there's any more information you can give me, I would appreciate it.

 

There might be a vacuum leak. Do you run the defroster all the time?

 

I did during the winter, but the mileage has been bad since day 1.

What exactly would a vacuum leak or running the defroster constantly contribute to poor gas mileage?

 

I had a 08 fit sport with manual. I average 37mpg 2 year average. This winter 32 mpg compared to 35 last winter, so I bought a scan gauge and tried to get my mileage up. I got it up to 42 mpg but had to drive 55 and coast a lot and was getting tired of driving it so I traded it in on a civic automatic and now getting 40 plus mpg on 3 tanks at 65 mph. I drive the same 26 miles one way so it is easy to keep it consistent. I know that running the lights and defroster will use twice the gas at idle. The reason I said that there might be a vacuum leak is that the engine will not throw a code until the fuel adjustment is over 20 percent. Try a different grade gas too.

 

OK, I've decided to go with Koi's advice and reset the ECU after I finish this last MPG test. It seems like something that isn't particularly difficult, and it couldn't hurt.

I'm just wondering the best way to go about that. Most people say removing the negative battery cable for awhile will work, but some people say you should only do it by removing and replacing the fuse. If I go that route, what fuse would I be looking for? I looked in my owner's manual and I don't see anything that looks like ECU.

 

When was the fuel filter last replaced?

 

I have no idea. Not since I've owned it, which has been a little over 6 months. I didn't know that the fuel filter was supposed to be replaced.