A lightweight oil
would be aroun 9-10 #/gal

olive oil is about .92 g/cm3 (or 7.68 lb/gallon), which indeed appears to be slightly less dense than water. 'course, the difference in molecular structure (disparate polarities) also keeps oil and water from playing well together =)

hi, tom ~ Yes, dear, i'm paying the bills this afternoon... just taking a wee break =)