Bought a set of these, they looked promising,24 LEDS in a reasonably high power IC package.Better than much of the non-name offshore stuff I've seen.http://www.autogoody.com/servlet/the-674/1156-7506-LED-Bulbs/Detail RESULTS:
Not quite there.
I'd estimate doubling the number of those specific LEDS would provide equivalent brightness. Really just a SWAG, I think the eye's response is Logarithmic?
Certainly not the reverse-lamp replacement they claim. As a tail light- maybe.
Compared both for brightness in an old Honda tail light rear assy to confirm.
'78 Lesabre rear harness below: