Any idea why? I keep a somewhat detailed log. after my oil change to mobil 1, i can't top 31 anymore. Other reasons? clutch? did i mess up something? air filter? etc
34.16 Chevron
33.30 Chevron
34.27 Chevron
33.57 Chevron
30.41 Arco gas
32.91 Olympian
34.46 Chevron
35.08 Shell
31.17 76 gas
29.01 76 gas (underestimate)
34.75 valero (overestimate)
30.14 Shell
30.85 valero
33.91 Shell
30.62 Shell
33.55 Chevron
30.93 Chevron (oil change)
30.93 Chevron
31.36 Chevron

 

I think the reason some are having MPG issues is the smaller under-powered Fit engine. I just purchased a 06 Civic Si and my first tank I got 28 MPG with 100% AC and around 75% city stop and go driving. I am sure I will get 30+ MPG on the Highway. One Very Important issue when it comes to MPG is throttle position. Use the gearing when you need power, stay off Wide Open Throttle..WOP..Down shift to get more power. The little Fit engine works awfully hard. My Si has plenty of power and doesn't need WOP to achieve the speed I need in everyday driving situations. Also the torque of the Fit Engine is weak. One big reason I choose the Si over the Fit was Power. If Honda would put the K20 into the Fit and call it the Fit type R then you would bhave a screamer, but that will only happen if the Fit will become the Hatchback that Honda needs, a performance Hatch..

 

I think your mileage is dropping because your TIRE AIR PRESSURE is not at 34 PSI. People overlook this a lot; it in fact affects your mileage quite a bit.

 

What did your oil use indicator show when you changed your oil? How many miles were you at?

I agree with Nexus, check your tire pressure as well. Also, have you been having more fun with the car after the break-in period? It's okay to say yes

 

yup i agree.. i was wondering why was my mileage dropping. I checked my psi and I was down to 28psi all around... DAMMIT and I work for a tire company! hahahaha!

 

maybe the tires are bad on some of the fits?

 

Gordio,

Did you change your oil filter as well? I followed the owners manual and only changed out the oil when service A came up. My MPG was dropping as well and I hoped that the oil change would fix it, but it didn't. It wasn't the tire pressure either. Last weekend I changed out the filter and the very next tank went back up to 34mpg. I started with 36mpg and was down to 26mpg the tank before the filter change. I'm coming up on 8000 miles and plan on changing the oil+filter every 4-5000miles.