In December 2014, my mom passed away, leaving me her Fit. It's a 2007 LX with a 3 speed automatic and only 5000 on the odometer. When I first drove the car, it seemed terribly underpowered, and the mileage was poor, averaging 15 miles a gallon in hilly San Francisco. I would not risk trips on the freeway as it struggled to go faster than 45 mph. My first course of action was to take the car in for service, as it needed fluids to be replaced, etc. I then added fuel system cleaner to a tank or two of gas. Mileage improved to approximately 19 mpg, and the car is now peppy enough to drive on the freeway. However, the mileage is still too low. I can report than when I start the car, there is a very heavy smell of gas. Thoughts?

 

Hilly San Francisco in an underpowered car with an anchormatic is a good recipe for low mpg. Run through a couple more tankfuls to see how things shake out, but under those conditions you're not going to see normal numbers.

 

In 2007 & 2008 there were only 2 models for the Fit, base & Sport.

Also both the base and the Sport shared the same 1.5 engine and same transmission. Since you noted your's is an automatic, it's a 5 speed automatic. The Sport added paddle shifters.

5000 miles the car is barely broken in. Would recommend the following if not done yet: oil change, air filter, spark plugs, coil packs. You should also reset the ECU and run it throw a couple more tanks of gas.

The Fit has no problems keeping up in the highway but if it's struggling like you say, it's not running right.

 

I bought a fit with high miles but it had been sitting a long time. I ran 4 tanks of fuel with 1/2 can seafoam per 9 gal of fuel and it really got it running, I get 21 around town and about 40 on the highway on level ground with the cruise on and the AC off. Mine had a bunch of small maint items that helped as well.

 

Heavy gas smell on startup could be a loose spark plug. Not very difficult to check on an '07 Fit since access to the rear of the engine is easier than 2nd gen ('09-13) where the wiper motor gets in the way.

You'll need a spark plug socket (I like magnetic ones, but that's just me) with an extension and a 10mm hex wrench to remove the coilpack bolts. Let the engine cool. Remove the coilpack bolts (plenty of DIY's here), remove the coilpacks, and see if any of the plugs don't seem to be tightened down correctly. If you can wiggle them with your fingers, that's a sure sign. Remove the plugs and inspect.

Plugs are cheap enough that even though the recommended replacement is 100K mi., you can get a set for ~$30-35 at places like rockauto.com. I'd stay away from any plugs except the Denso and NGK iridiums, but that's just me.

A torque wrench also comes in handy for putting the plugs back in. If you don't have one, don't go all deathgrip on tightening them down. Snug but not crazy tight, as you risk cracking a plug if you overdo.

If you're not comfortable with all this, have a mechanic do it. Let us know how it works out.

 

Spin plugs down finger tight then 1/4 turn with the ratchet is what the Plug manufacturers usually recommend. YMMV..

 

Thanks for all of comments and suggestions. I won't be able to address this issue until some time this summer. I'll update my experience then.

 

If you have a loose plug, by summer you could have a blown out spark plug. Once they get loose they can pop out taking the threads with them.

 

No worries. The car is in SF. I am in PDX. The car won't be driven until I get back down there.