HRC say 30:1, and why should you argue?

Way back when Grandma was a boy we tested 747 at 20:1, 25:1 etc. up to 80:1, on track and on dyno. Also sat in on Castrol tests at their technical centre with tests up to 400:1! They all looked close on the dyno, but track testing worked best at around 25~30:1. 40:1 ran hotter. 20:1 lacked snap off the corners.

My 300, Pauls 300 and the NRS run 30:1. My CR500 Supermoto runs 40:1 ('cos it doesn't rev)