The oil filled can coils will melt down and short if wired to full battery voltage. GM can coils had internal resistance built into the coil so it was wired for full battery voltage. Ford used a resistance wire to the coil to cut down the voltage. This had the downside of weaker spark when cranking. Chrysler used the famous .5 ohm/ 5 ohm resistor to cut down the current. The .5 was for cranking and the 5 was the running one. Hotter spark cranking. But also caused the start and die syndrome when the 5 ohm would burn out.
And what about candlepower? I remember the old 1157 bulbs were 3 and 32 CP and 1156 was 32. The manufacturers like to play with CP, the flashlights with 2 bazillion candlepower...lol
