My current car is an EB II XR-8 1 and I run it mostly on BP Ultimate or occassionally on Shell Optimax, gives me better response time and better ecconomy. I have a BA XR-8 on order and would think I would keep it on those types of fuels. I think they are both 98 Octane. What do you guys use? Also I heard that because the Shell refinery in Geelong and the BP refinery is in Brisbane (interstate either way) they use each others fuels to cut transport costs, is this true? When you fill up with BP Ultimate are you really filling up with Mobile or something like that?