This relates to how well the light fixture dissipates the heat generated by 40w or 60w incand bulbs.
I've read where LEDs put out 4x the lumens output vs an incand's lumens output.
Your ratio is 7.5:1 so maybe your LED is very efficient or the maker picked a test method that makes it look good.
A recent patent for an LED with many pages of text & drawings does not once claim a luminous efficiency, lumens per watt, so the vendors can claim whatever they want.
Who's going to check?
