Performance car drivers use BP's 98 Octane as it has a better reputation than Caltex's. Could be hard to prove but my local tuning shop reckons it sticks out like dog's balls when it comes to a Dyno-tune.

Personally I use BP98 first then Caltex 98 even though the book says only minimum 91 octane. Others I have met say they get much better mileage out of high octane so its worth the extra bucks.

All the bike shops I have dealt with have recommended Caltex Vortex I even put it in the dirt bikes Ive had

when I was getting the bike Dyno'd down at Wayne Patterson they said to use only 95... either BP or Caltex. Apparently 98 blackens up everything... said it came from SWHD. To be honest I find very little difference between 95 and 98.