I read quite a good article in Bike mag this month about chasing the highest bhp. One thing the makers do is raise the maximum revs the engine can do & so can increase the bhp. Have a look at a dyno graph of the new bikes compared to the older model usually the bhp is there abouts the same until the last 2K or so revs. According to Bike mag the older Yam R1 has more bhp through the low & mid range than the new one but the new `un can rev higher & so get more bhp. The 110 bhp BM engine must use 98 RON petrol too.