a common mistake when buying LED's is that people assume MORE LED's = BRIGHTER
there are 2 common types of LED's, 5050smd and 1210smd
each 5050smd is as bright as 3 1210smd, so a 6smd 5050 festoon bulb is as bright as a 18smd 1210 festoon bulb
so for maximum light output, use 5050smd's, check out
www.automationLED.com