My two cars run on one of the following (depending what's available... all are 98RON):
- BP Ultimate: Good fuel, get better economy, and is cheaper than Optimax
- Shell Optimax/Mobil 8000: Good fuel, a bit better fuel economy than on reg. unleaded, but sometimes bloody expensive
- Caltex Vertex Gold: Good as well, between the prices of BP Ultimate and Shell Optimax/Mobil 8000
BTW I've got a 1993 Soarer 2.5GT and a 1999 Tarago in the driveway, and both get treated to 98RON fuel