Quote:
Originally Posted by groar
What are your rpm and gear at 55 and 69 mph ?
At which rpm is your best torque ?
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That's in fifth gear, but I don't have a tach so I don't know the rpm right off hand. The GA16DE engine in my Sentra has a broad torque peak from about 3200-3800 according to listed specs.
I agree that, in general, reducing speed will improve mileage. That's inevitable since the air resistance scales with the square of the airspeed. If a person is driving numbly, with no other care than maintaining a constant speed, they will probably get small but consistent gains from travelling at a lower speed.
The problem is this: the idea that reducing speed will always reduce fuel comsumption is based on an oversimplification. What's oversimplified is the assumption that the engine is equally efficient at all rpm and load conditions. The success of P&G techniques highlights the gross inefficiency of lightly loaded piston engines.
I was really amazed at the 74 mpg I was getting with the P&G technique. I'm trying it around town as I commute to work and such. It will be interesting to see how it works at lower speeds.