One of my mates has recomended I use the following for petter performance and fuel economy. Can anyone advise if this is correct. Sparkies - ..ngk iridium IX or better, like laser iridium. Should be rated for 100,000 kilometers. Transmission oil - Castrol Transmax Z. Engine oil - Royal Purple 5W30 grade. Genuine Toyota Air and Oil Filters Looking forward to your comments.