For the same power level, your friend is right, all-cruise will get you there sooner and spend more energy than cruise-and-coast, because you are making cruise power only part of the way instead of all the way.
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Genesis 49:16-17
"Well, well!" said Holmes, impatiently. "A good cyclist does not need a high road. The moor is intersected with paths and the moon is at the full."
Last edited by Darth Lefty; 09-01-15 at 12:02 AM.