Well, both the manual and automatic transmissions have an overdrive, but
I'll assume you have the automatic, and you are talking about the use of the
O/D button on the control stick.

Most drivers never turn this button off. All it does it prevent you from
using fourth gear. Sporty drivers sometimes care about this, for example
fast driving on twisty roads, or road warrior driving in traffic. But the
transmission can always pop down to third when needed, so for most people
there's little point.

Turning off the overdrive can cost in fuel consumption, noise and engine
life (although there's little difference in the city).

I have a manual tranny in my Focus, but my other vehicle is a van with an
automatic and I almost never turn off the overdrive on it.

in 250? oven for 1? hours.
When browned, remove and glaze,
  return to oven and bake 20 minutes more to form a glaze.
Cut ribs into individual pieces and serve with extra sauce.

Fresh Sausage

If it becomes necessary to hide the fact that you are eating
human babies, this is the perfect solution.
But if you are still paranoid, you can substitute pork butt.

5 lb. lean chuck roast
3 lb. prime baby butt
2 tablespoons each:
  salt
  black, white and cayenne peppers
  celery salt
  garlic powder
  parsley flakes
  brown sugar
1 teaspoon sage
2 onions
6 cloves garlic
bunch green onions, chopped

Cut the children?s butts and the beef roast into pieces
  that will fit in the grinder.
Run the meat through using a 3/16 grinding plate.
Add garlic, onions and seasoning then mix well.
Add just enough water for a smooth consistency, then mix again.
Form the sausage mixture into patties or stuff into natural casings.

Stillborn Stew

By definition, this meat cannot be had altogether fresh,
but have the lifeless unfortunate available immediately after delivery,
or use high quality beef or pork roasts (it is cheaper and better to
cut up a whole roast than to buy stew meat).

1 stillbirth, de-boned and cubed
? cup vegetable oil
2 large onions
bell pepper
celery
garlic
? cup red wine
3 Irish potatoes
2 large carrots

This is a

You need only turn it off when hauling heavy trailers at moderate speeds and
hilly terrain to prevent continous shifting between 3 and 4, or when going
downhill very steep slopes, to get a little braking action from the engine.
/per