Crappy Fuel Mileage

[JAO]

I own a 2012 Ford Fusion SEL 3.0L V6 FWD in Southern California. I just purchased the vehicle in February of this year as a CPO vehicle from a dealer.

I drive mostly city roads and can not get more than 14.5 mpg. I do not drive aggressively and I'm babying the pedal more than I ever had to with any other vehicle. My wife owns an '08 mustang GT with a 5.0 5-speed manual V8 and I drive that aggressively. i get just about the same mileage in her car.

Tires are inflated to 35 psi, alignment seems okay and I just replaced the transmission fluid, which was dirty. I also replaced the air filter just in case. The car has only $18,700 miles on it which makes me wonder why the trans. fluid was dirty. The transmission also shifts late in the low gears, which means the car is reving higher than it should by the time it shifts to the higher gear.

Any ideas why I'm getting 14.5 instead of an mpg closer to the 20 mpg EPA estimate?

[miacsin]

I solved this one!

 

Replacing an upstream Oxygen (O2) Sensor restored my fuel economy.

3.0L 2007 SEL AWD, so far replaced front upstream sensor.

Nothing appeared wrong with any sensors (no codes) but yet my fuel economy went from 9 mpg city and 18 highway back to factory normal (about 18 city, upper 20s highway).

I am waiting on another sensor from the dealer to replace the rear upstream sensor.

 

I have searched the forums and google for this fuel economy problem for the last two+ years and every 'expert' almost unanimously says not to replace the O2 (Oxygen) sensors unless there is a code. I finally decided to buck the opinions to replace them and it worked.

 

Background:

Car when new had excellent fuel economy, but around 50,000 (K) miles fuel economy went down, and became worse over time.

Strangely enough, using cruise control restored most of economy (about 10mpg+) even when comparative pedal input was steady on flat road.

The car now has over 80,000 miles with new O2 Sensor and fuel economy restored to new.

 

It is cold in Nebraska now. I've noticed that with town driving only that I'm getting around 14 mpg. I hope this isn't normal but just curious
if other owners are getting the same results. If I can go highway driving I'll get 29 or 30 mpg. My car is an 09 SEL V6 with 220 hp and no
mods of any king. I can roughly go 250 to 270 miles on a tank with town driving. Any info would be appreciated.

Kevin

[Rok]

There is a HUGE difference in the power-to-weight ratio between the Corvette and the Fusion. It takes less power to propel the 'Vette than it does to move the approx. 1000 lb heavier car.

My Dad commonly sees 29+ MPG in his Z06, driving it conservatively. Jekyll/Hyde personality when you hammer it :-)