MPG v.s Speed (rpm), General question Options

[95BlueGT]

Ok here is the Situation:

You car gives 30 Miles to a Gallon at 70Mph. At 70mph ( last gear ) you are in the middle of your powerband. The distant you have to travel is 33 Miles. You have only 1 gallon of fuel in your car.

What do you do? Do you slow down your car burn less fuel? OR do you speed up?

All road and air conditions are ideal.

[saleeka]

erm... I say slow down- increasing enigne speed also increases rate of consumption. even though in theory you may get peak fuel economy at peak torque, who is to say you are required to use ALL that power to mantain speed? All that happenes when you maintain peak torque is use excessive power in most cases, and keep the engine closest to a set point without much deviation if you did need that power... It increases fuel economy much in the same was cruise control would- you keep the car at a constant. If you were to get best fuel economy at peak torque, 5th gear would be geared higher in out GT's. 65 mph in a GT is 3200 rpms- 1000 or so rpms below peak torque. Of course there are certain variables to consider- reducing rpms also reduces speed, and there will be a point where the reduction in speed will result in longer periods of consumption, and so on. Remeber- a basic concept of physics is the the more energy somthing puts out, the more energy it consumes.