Optimax -it works just like shell says it should.
Worry - Shell says that Optimax does everything we have been saying it does! Its suppopsed to be better mid range, it supposes to pull away better at roundabouts, it supposed to give better fuel consuption on long journeys.
AND it weighs more - its actually 10% more dense than ordinary unleaded. And it works by being more highly refined and having all the olefins and non-oxegenators you can imagine. Its sold in Australia and the UK only though - because the pollution levels of some of the gases are lower on some levels but higher on others. well thats how i read it.