You made me think... on re-checking the manual (mine's a 2006 model) it does say at least 91 octane, but 95 is recommended "for better performance". I'll have to give it a try and see. We don't have 98 octane Shell around here, and the BP is always morer expensive thatn the others, so ll give the Caltex a go.
Loshio I have no doubt that you are getting better fuel efficiency but how much?? I have tried all 3 (91, 98 & E10) and I notice very little difference in efficency. On my last road trip Melbourne to Bega I got about 60klms less on E10 when the vehicle was running at 8.4L/100, I was getting 630-660 out of a tank. This was just cruising speed with the odd firm foot plant to get past the caravan conveys... I have previously tried 98 and I got all of 80klms further.... At an extra 12cpl in my opinion it wasn't worth it. Different horses for different courses and if you have the money and you want to spend it go for it.
For what it is worth I manage 1400 vehicles, most LC's and my account with Caltex is 450K p/m, anytime I talk to them about high octane fuels they grin from ear to ear.... I am sure they would be happy to see an extra couple of G's in my invoice each month.
Cheers,