Success finally.... After three months of trying, I finally got the MPG I knew this Focus had in it. All the MPG-related changes I've done to this car were done one-at-a-time, after which I reset the computer and ran a complete tankful of gas through it, and calculated the mileage. I did have some MPG variation from tank to tank, but the mileage remained constant from 25-26 MPG. The tankful before this last change got me 25.5 MPG.
What I drive....
2006 Duratec ZX5 2.0 automatic. (purchased used 5-08)
25.8K on the odometer.
New Sumitomo tires, stock wheels.
The most recent PCM program according to Ford.
St Louis Missouri...altitude about 600'.
Temperature during most testing....80-90F.
50/50 mix of city/highway during most testing.
Conservative driving....trying for the best MPG.
AC on all the time, except for a test tankful with the AC off.
What I did (unsuccessfully) to try to improve MPG....
Oil change to 5W20 Valvoline.
New fuel filter.
New plugs NGK J-Power copper core (tried various gaps .050 now)
Extra ground wires (2/3 of the big three)
Tire pressure...36psi w/recent alignment.
Tried different fuel system cleaner products...BG the last which I know to be excellent.
Tried four different gas brands (all are 10% ethanol in this state).
In short I did everything I could to get better MPG....nothing much changed. The mileage varied only slightly for the three months of testing/work.
What finally worked......
![Image]()
A Steeda SRI, which replaced the complete Duratec intake system (I removed the lower filter housing complete). At the same time I added a lower fan blowing upward at the Steeda, which lowered the intake temperature about 25F. (I can't be sure if this had any effect on the MPG...probably not much if any)
![Image]()
During the Steeda install I left the plastic airflow straightener in place....supposedly this is not necessary.
My take on all this....The stock air-filter is supposed to be good for 100k. I got the car used three months ago, so I don't know how the car was driven before, or under what conditions. But the plastic vacuum indicator was in the green.....the air filter was supposed to be ok.
I had a Ford MPG test done at a dealer a few weeks ago....they found nothing wrong, and the mileage checked "normal".
If that is true, the only explanation is that the stock Ford intake system on this model, is way too restrictive, way too long. That's what the Steeda SRI fixed......nothing else. During the Steeda install I used the original MAFS over, without cleaning it. I'll try cleaning it after the next tankful....confirming that my improved MPG is for real.
So what MPG am I getting now......28.5 MPG. That's a plus three MPG change with a new air-cleaner assy and nothing else. Pretty damn good for an automatic with the AC on all the time. I'm starting to like this Focus.....(YMMV).
Oh....more info/photos of my unusual extra fan(s), can be found in this thread.
And for general information on this MPG thing.....visit this sticky thread
What I drive....
2006 Duratec ZX5 2.0 automatic. (purchased used 5-08)
25.8K on the odometer.
New Sumitomo tires, stock wheels.
The most recent PCM program according to Ford.
St Louis Missouri...altitude about 600'.
Temperature during most testing....80-90F.
50/50 mix of city/highway during most testing.
Conservative driving....trying for the best MPG.
AC on all the time, except for a test tankful with the AC off.
What I did (unsuccessfully) to try to improve MPG....
Oil change to 5W20 Valvoline.
New fuel filter.
New plugs NGK J-Power copper core (tried various gaps .050 now)
Extra ground wires (2/3 of the big three)
Tire pressure...36psi w/recent alignment.
Tried different fuel system cleaner products...BG the last which I know to be excellent.
Tried four different gas brands (all are 10% ethanol in this state).
In short I did everything I could to get better MPG....nothing much changed. The mileage varied only slightly for the three months of testing/work.
What finally worked......
A Steeda SRI, which replaced the complete Duratec intake system (I removed the lower filter housing complete). At the same time I added a lower fan blowing upward at the Steeda, which lowered the intake temperature about 25F. (I can't be sure if this had any effect on the MPG...probably not much if any)
During the Steeda install I left the plastic airflow straightener in place....supposedly this is not necessary.
My take on all this....The stock air-filter is supposed to be good for 100k. I got the car used three months ago, so I don't know how the car was driven before, or under what conditions. But the plastic vacuum indicator was in the green.....the air filter was supposed to be ok.
I had a Ford MPG test done at a dealer a few weeks ago....they found nothing wrong, and the mileage checked "normal".
If that is true, the only explanation is that the stock Ford intake system on this model, is way too restrictive, way too long. That's what the Steeda SRI fixed......nothing else. During the Steeda install I used the original MAFS over, without cleaning it. I'll try cleaning it after the next tankful....confirming that my improved MPG is for real.
So what MPG am I getting now......28.5 MPG. That's a plus three MPG change with a new air-cleaner assy and nothing else. Pretty damn good for an automatic with the AC on all the time. I'm starting to like this Focus.....(YMMV).
Oh....more info/photos of my unusual extra fan(s), can be found in this thread.
And for general information on this MPG thing.....visit this sticky thread
