Cruise control VS fuel mileage

There are lots of bays around, Hudson, Chesapeake, Buzzard’s, Barataria, Mobile,…

That is what the broken line is for. If there isn’t one, the economical driver should be willing to STOP at the top of the hill and let folks by.

Professional drivers, trying for the best possible fuel economy, will gently accelerate going DOWNHILL letting the hill add to the stored kinetic energy, and then gradually decelerate going UPHILL, letting that stored energy (instead of more fuel) push the car up the hill… Cruise control can’t do that.
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I have obtained some of my best gas mileage doing just the opposite. Accelerating aggressively to a low top speed and using the engine on the climbs while letting gravity power the car on the downhills. I try to keep my average speed as high as possible with the lowest possible top speed. In other words, as steady a speed as possible.
The theory behind this is that gasoline engines typically have a peak efficiency at about 60% full power so my engine is either at its peak efficiency or its doing nothing while my car coasts.
I tried the slow and lazy acceleration thing and my gas mileage wasn’t as good.
The nice thing about driving this way is other drivers will never guess you are up to getting good gas mileage, except when you coast to the red lights that they charge up to.

My best so far was a 46 mpg tank with a Toyota Yaris EPA rated at 29/36 mpg tested the “new” way.

So pretty much you are saying that the only reason you use cruise control is so you dont get a speeding ticket? I guess to spend the few extra dollars in fuel in mountainous terrain is a better price to pay than a ticket.