How this started:
In Whitehack 3e, I created a character and bought “Oil (lamp), 1 pint”.
How long would that last?
From OSE’s Adventuring Gear:
Lantern: Can be closed to hide the light. Burns one oil flask every four hours (24 turns). Casts light in a 30’ radius.
From The Google:
For every gallon of oil burned 1/4 – 3/8 inch of wick is consumed. Oil lamps/lanterns burn about a 1/2 ounce of oil per hour. A gallon of oil will last you 512 hours! This generalization will significantly vary depending upon the size of your wick, type of oil, height of wick, among other variables. The point: a small amount of oil will go a long way.
Conclusions
1 pint of oil (20 Oz) will last around 40 hours. Not sure how they got 512 for a gallon (1 gallon = 8 pints = 160 ounces = 320 hours).
I am Starmonkey 