Hi. I bought my Fit in April 07. I don't put many miles on it, so I just got my first service a couple of weeks ago. Oil change, tire rotation, and SRS Wiring recall.

I use scanguage and hypermiling techniques (esp. lots of coasting), so I was getting good gas mileage. Even in winter, all-city driving I'm getting avg of 34 (summer averaged about 37.5).

BUT after the service, I can already tell (esp. with the scanguage, but even without it) that something is different. MPG is down 15-20% for trips, and the engine is idling about 1.5 to 2k higher (used to be low to mid 800s, now it is 950-1500).

I haven't completed a full tank yet (finished off one after service that only got 32 mpg), so maybe its premature. But I'm wondering if anyone has any ideas or similar experience. I read about ILP on here (thanks!), and will be trying that. I saw that as part of the wiring harness recall, there was a computer update for the airbag timing...maybe an ILP is needed after that?

Thanks.

 

I would say that would have had to unplug the battery to install the wiring harness, and that you would need to do the ILP. Let use know how that works out.

 

You mention winter driving, well using the defrost will sap your mileage about 30-50%. The AC compressor is a power hog when in use.

There is a mod that when done correctly, will make it so that the AC compressor will not be turned on while you are in Defrost mode.

 

My guesses:

1. As Cptan said, disconnecting the battery probably reset your computer, while it is re learning mileage will suffer. Search for ILP. If I remember correctly you just have to drive at a fixed throttle position for 2+ minutes.

2. They put the wrong grade of oil in.

3. Have you calibrated your scangauge? That is, resetting it at each fill and entering the amount of gas you pumped? If not your gauge could be several MPG off.

 

Thanks for the help. It has been 3 tanks since the ILP and the idle & mileage are back to normal now. smatts, thanks for the tip about defrost, I never would've thought something simple like that was a mpg killer. Thanks again, you guys rock. Love this car.

 

Check the oil level and tire inflation.

If the ECU does not reset and return the idle RPM to the 750 range HOT, set up an appointment with Honda as they busted your Fit.

good luck

 

I am very intrigued by your suggestion about modifying the defroster, bypassing the AC compressor.

I own a 2008 Fit Sport (automatic). My driving is mostly 90% city-based. I have to fill up today, after driving less than 200 miles on the present tank. We had a period of very cold weather here in central Illinois, so I had to use the defroster several times. I also find leaving the house for work and driving off without allowing the car to warm up to the point of letting the "Engine cold" light to turn off.

With all this in mind, I am very disappointed in the mileage, especially in the winter. What can anyone recommend I do to ensure good MPG? And specifically, what were the modifications to the defroster that were recommended earlier? (Who should/could make those modifications?)

Many thanks!

Joe