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Jim Chill
Jim Chill, Technician
Category: Car
Satisfied Customers: 590
Experience:  15 years Ford dealership experiance 25 years all makes and models
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Mercury marquis: my 2010 SHO will only average 22 mpg

Resolved Question:

I have had a Crown Vic that averaged 24 MPG; a Mercury marquis that averaged 25 mpg; a GT Mustang that averaged 24 mpg, so why is it that my 2010 SHO will only average 22 mpg?
Submitted: 7 years ago.
Category: Car
Expert:  Jim Chill replied 7 years ago.
The sho has 100 more hp than the crown or the mercury and at least 50 hp more than the mustang gt. I am sure that will make a difference in fuel consumption. Have your Ford dealer do a relative fuel mileage check on your car and check the fuel trims to make sure everything is operating normal.
Customer: replied 7 years ago.
I would think more hp would equate to less throttle position and therefore better mileage. We have been pretty conservative on using the power of SHO and we drove the wheels off the mustang, even competition racing it! Even on those days the average never went below 19 mpg. I find it hard to believe that a 4.6L V8 would get better mileage than a turbo'd V6. What about the sooty exhaust?
Expert:  Jim Chill replied 7 years ago.

I was thinking about the exhaust and the only thing i can think of is if your driving more conservatively than it is more liable to produce carbon build up and that is burning off causing the sooty exhaust. the dealer can look at the fuel trim and injector flow to make sure everything is in spec.


TSB 9-23-8 I don't know if you had this concern or if it applies directly to your SHO but your dealer can tell you your latest cailbration and update if needed.


Some 2010 Taurus, MKS, MKT and Flex equipped with Gasoline Turbocharged Direct Injection (GTDI) engines and built on or before 10/14/2009 may exhibit diagnostic trouble code (DTC) P0096 intake air temperature: (IAT) sensor 2 circuit/range performance on bank 1. This may occur when the engine is at operating temperature and the vehicle is shut off and then restarted within five seconds.
Reprogram the powertrain control module (PCM) to the latest calibration using IDS release 63.12 and higher or 64.01 and higher. This new calibration is not included in the VCM 2009.9 DVD. Calibration files may also be obtained at

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