Getting 11mpg (city) on a 2007 Sport w/ 108k - Any Suggestions?
 

Hey yall I'm new to the forums, so please point me the direction of a relevant thread if this is redundant-

So I just bought a 2007 Fit Sport w/ 108k miles, auto transmission, and it's getting 11mpg in the city (LA).

Bought from the original owner, always maintained at the dealer, always on time, with records (on carfax, not hard copies). The records show it got it's 100k treatment, and more recently vavles adjusted, tire pressure checked, serpentine belt replaced, safety check. I also had it looked over by a highly rated mechanic before purchasing.

It's currently at a mechanic who found nothing immediately visible that's causing the problem- they're doing a fuel system cleaning and replacing the air filter, but they said this does not guarantee to fix the 60% fuel economy that's currently lost.

Any suggestions?

Just two questions before anybody suggests a mechanical solution: how do you know you are only getting 11 mpgs? Are you calculating the number manually or are you relying on what the computer says? Secondly, since you bought the car from the original owner, the very first thing I would do is call them up and ask them. If they were getting 11 mpgs, they certainly would have noticed it as well.

Fuel system cleaning will INCREASE fuel usage (harsh chemicals cause injectors to leak).
What are your car RPMs at 40 mph? 60 mph? how many minutes a single trip last?
Also go to the smog station and perform 2 speed idle test and ASM 25 (treadmill) test. Post results here!!

Every time the car isn't moving, it's losing gas mileage.

Sitting still in traffic? Stop lights? ZERO miles per gallon. That zero still calculates into the average MPG per tank.

Fill the tank....Get on the highway and go 200-300 miles at rock steady 55 MPH and you will see it gets decent overall gas mileage.
If you calculate it correctly.

hey thanks for the reply. of course i contacted the seller right away. havent heard back but its only been a few hours.
i should clarify, this is not an average mpg over the course of multiple full tanks.
i bought the car yesterday with a 1/4 tank and it went down to empty unusually fast. i live in NE LA, this was not terrible stop and go traffic. very little time spent fully stopped.
I filled up started the trip calculator. filled up again after driving 34.8 miles and found that i had burnt thru 2.98 gallons. same traffic conditions,
thats 11.64mpg.
not a long term average but certainly call for alarm.

hey thanks, i'm fully aware of the dynamics of fuel economy regarding traffic conditions. please see my reply to the previous comment for more info. thanks.

hey thanks for the reply,

thats good to know about the fuel flush. they just performed it. replaced the air filter too.

my rpms at 40 were about 1600. didn't get a chance to get on the freeway before coming home just now.

what will the idle test cost and what kind of info will the results provide?

rpms at 40 were about 1600 sound about right
the fuel gage itself is very inaccurate (shows less than 1/4 but scanner reads close to 30%)
the emission test test will provide CO concentration in the exhaust (high CO - higher fuel use) ,as well as combustion efficiency.
If you have recent smog report from seller, post results here

Don't rely on short term data. As Ezone suggested in Post #4, fill up the tank, drive a few HUNDRED miles (get to know the car!), then fill up again on your way home.

Report the results of that test. Divide miles driven by number of gallons.... the car's trip calculator may not be accurate if the battery was recently disconnected.