Before revision: The energy conversion process used by an ASRG is about four times more efficient than in previous radioisotope systems to produce a similar amount of power, and allows it to use about one quarter of the plutonium-238 as other similar generators .
After revision: The energy conversion process used by an ASRG is significantly more efficient than in previous radioisotope systems , using one quarter of the plutonium-238 to produce the same amount of power .