More importantly, the annomoly would show up in the num,bers. There is no evidence to suport EITHER fuel being more or less "unreliable" in jab engines that im aware of. If 98 octane was causing issues, then im sure we would be onto it by now., The fact is there seems to be no common denominator. We have looked, hard. The only real thing we have noticed, is that blokes who do NOT follow the advice from Jab seem to have a better time. I dont mean that in a nasty way, its an observation.