i've got a fairly new jazz 1.5, auto. was initally driving on normal unleaded from caltex/safeway stores. i then tried the 95 octance from caltex/safeway petrol stores. that was crap, as there wasn't much difference.

then i noticed the car was idling rough. like at the traffic lights i the car would "vibrate more" making it feel like a mini massage.

then tried shell v power. yea there was a difference, little smoother, and a little less roughness at the traffic lights.

then tried BP 98. Best out of them. idle problems gone, feels heaps better and smoother. yet to try mobil though