Ok, over the past few days since I originally posted this question I have noticed guys talking about all kinds of different numbers. Like someone was talking about B99, B24, B25, etc. Why all the different ratios? I mean, why would someone or company go to the trouble of making B99 when they could just go all the way? I understand the "need" for a B5 if that's what the manufacturer will approve of, but why all the different (and sometimes so little difference) numbers??

Perplexed!