|
Although pumping losses are reduced at wide open throttle, it has been my experience that the pumping losses are a lot less than the loss of efficiency caused by running at high manifold pressure (low vacuum). I have always gotten the best mileage when running at Max Torque RPM with the highest manifold pressure possible - which translates to as little throttle opening as possible. At max torque you require less throttle opening for a given power output than at any other speed. Of course, doing this in top gear is obvious.
Some vehicles will get you a speeding ticket on just about any highway at peak torque in high gear. On my Ranger 4.0 2400RPM in top gear is 120kph (3.55 gears and 225-70 16 tires) On the 1975 Celica GT I drove years ago it was closer to 85 MPH,( and with a light foot at that speed 42mpg was not a problem.)
|