Deja vu...
I ended up running my old BMW on 98RON fuels - because that is what it was designed for. No pinging!
I drive out of BP servo's that only have ULP and Ultimate when I go to fill our current cars. I have been saying for a couple of years, and I think I posted it in here once before, that I have found no discernable difference between PULP and the 98's in either of these cars, besides the fact that the 98 stuff is dearer.
I am not sure that Vortex is actually a 98 - I thought it was a 95-96?? <edit: there is a Vortex 98 - name says it all> I know it isn't as dear as Ultimate, Optimax, etc...but our Clio seems to run better on Vortex than anything, though I don't have any empirical evidence to support this - though I average 5.6L/100km - I think the XJ uses somewhat more than that
I don't understand people that try to save money putting lower grade ULP fuel in cars designed for PULP - all it does is increase consumption and make it run like junk negating any savings. But then, I remember rule #1: People are idiots, and it all makes sense again...
Isn't it funny? You'd have thought with leaded petrols demise fuel choice would have been limited to two types...no! Now we have ULP, Ethanol blend ULP, PULP, Ethanol PULP, 98 PULP, some new Ethanal blend 100 RON...
It is marketting and gimmickry at its finest, folks.
PS
I can certainly say that driving style plays a very large factor in fuel consumption. Patient and steady saves roughly 20-30% over impatient people that need to swap lanes every 3 seconds to make roughly 2 seconds total gain on their trip of 30km...if you are in fairly heavy traffic, just relax, face the fact that it will take a bit longer this time, and just keep the pace steady. You'll save heaps without spending any extra on gimmicky fuels...