Q: When refining crude oil to produce diesel fuel, I understand that compared to gasoline it takes less refining. Is the yield in gallons per barrel greater?

WALTER SIKORA, Athens

A: The refining energy efficiency of diesel has a slight advantage over reformulated gasoline, says Don Anair, senior analyst for the Union of Concerned Scientists, but the actual yield in gallons of diesel per barrel of oil is less than gasoline.

This is important when comparing the global warming emissions from diesel and gasoline vehicles, Anair said.

A diesel vehicle may get a 30 percent to 40 percent improvement in miles per gallon over a gasoline vehicle, but the reduction in greenhouse gas is closer to 15 percent when accounting for the higher energy and petroleum content of diesel fuel.

Q: What happened to Paul Harvey?

EVELYN ROBERTS, Hampton

A: The 89-year-old Chicago-based radio icon is back on the air part time after recovering from pneumonia, bronchitis, cataract surgery and the death in May of his beloved wife, Lynne "Angel" Harvey, according to ABC Radio Networks. Harvey is telling us "The Rest of the Story" on a full-time basis, but has cut back on his daily news duties.

You can hear him on the midday news several times a week. There has been no announcement on when he'll return full time to his "News and Comment" show.

-- Researchers Joni Zeccola and Sharon Gaus wrote this column.