You would need to shoot Nulon off an email, I would like to know also. Prenrite state clearly in their product information sheets that Racing 10 is synthetic PAO and Ester based.
If you're looking for something a little cheaper, I have been using Penrite HPR DIESEL 5 5W-40 It has a high Zinc content as well as detergent/ cleaners, works well for me.
http://www.penriteoil.com.au/products.php?id_categ=1&id_fuel_type=3&id_products=7