The Illusion of Miles Per Gallon

Quiz time: Which of the following would save more fuel?
a) Replacing a compact car that gets 34 miles a gallon with a hybrid that gets 54 m.p.g.
b) Replacing from an S.U.V. that gets 18 m.p.g. with a sedan that gets 28 m.p.g.
c) Both changes save the same amount of fuel

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