Does anyone scientific know if an oil lamp with 8 oz of oil burns better than one with 5 oz?

Question

The question is if all conditions are the same such as wick size, quality of oil, etc. If one did a measure of the heat omitted or the quality of the flame, or some other test, would there be a difference?

Answer 1

Yes, a lower oil level will have a slight effect on the flame properties.

The wick is maintained saturated with oil due to the 'Capillary' effect of the burning vapour causing a slight vacuum in the wick due to convection which draws up the oil.

The further down the wick is the level of oil, then the less effective this action, resulting in a little less oil available for vaporisation giving a slightly weaker flame and a little less heat emitted, all probably only measurable by sophisticated equipment...

Answer 2

If it did, the performance of the lamp would decline as the fuel was used up.  And from what I've seen, a lamp works about the same as long as there's any amount of fuel in it at all.