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3.8 fuel economy.

Discussion in '1994-2004 V6 Mustang Tech' started by dgb1940, Mar 7, 2018.

  1. dgb1940

    dgb1940 Member

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    Has anyone found a way to improve the fuel economy? I know on a manual it's a bit better but I own an automatic.
    Has anyone swapped out the tranny at changed residents or how did you do it?
     
  2. six gun

    six gun Active Member

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    Personally I found fuel economy gains from both underdrive pulleys and a tune from my handheld engine tuner. Along with general tune-up stuff. Before I started messing with rear end gear ratios I went from about 25mpg highway stock to almost right at 30mpg.
     
  3. dgb1940

    dgb1940 Member

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    Under drive pulleys?
     
  4. six gun

    six gun Active Member

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  5. Aldhissla

    Aldhissla New Member

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    Good plugs and coils, tire pressure and keep it clean. Best way.
     
  6. 08'MustangDude

    08'MustangDude Active Member

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    It's a smaller crank pulley, it slows down the turn rate of all the other pulleys, thus less drag
    on the crank. That frees up the parasitic horse power loss at your water pump, power steering
    pump, A/C compressor. Does not ADD horsepower, just frees up some, less drag on the
    motor so more gets to the wheels.

    Winter, always less MPG. Colder air is more dense, more drag on the vehicle. Snow on
    the roads means more road resistance. Colder air = more fuel as well, so you lose
    up to 3MPG in cold weather. I see it on my display on my other car. 33MPG when it
    gets cold, and 36-37 once it's over 40 degrees.
     
  7. Bullet1992

    Bullet1992 New Member

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    I have an 03 convertible and I've noticed that if you keep it out of overdrive unless you are 45mph or faster I can get 23 to 26 mpg around town and 28 30 on interstate. Learn to be light on the throttle when you take off also
     
  8. Arthur

    Arthur New Member

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    Those pulleys are expensive. I can't see spending that much to save a very little on gas not to mention all the work to change them out.
     
  9. Poco

    Poco New Member

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    I changed out all the fluids, engine, tranny and rear end and I could feel a big difference in the performance. My Mustang had been neglected so a tune up with new spark plugs, wires, coil pack and air and fuel filters were replaced. Today I changed out the wheel bearings on all fours. I felt with 120k miles on it , that type of preventative maintenance wouldn't hurt.
     
  10. 99applemustangdudesixauto

    99applemustangdudesixauto New Member

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    At 175,000, six and auto, I did the 100,000 mile tune up again (first one was at 80K) - original coil paks, and original wheel bearings - just replaced one exhaust manifold also for a cold "ticking" noise for a minute or so -
     
  11. 99applemustangdudesixauto

    99applemustangdudesixauto New Member

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    What is the effect of using the under drive pulleys, and slowing down the accessories? Effect on power steering, alternator output, etc?