Here's the complete listing
of all the products on sale at Supercheap. Note you'll probably have to enter your postcode, then reopen the URL to get it to show you the catalogue linked.
Here's a quick break-down of the products offering the biggest savings at present:
35% off selected Shell Helix and Castrol oils (HX7 10w40 and GTX 15w40; $25.79ea for 5L)
30% off Castrol Edge 10L 5w30; $89.99ea
20% off Castrol RX 15w40 Diesel 20L; $97.90ea
20% off Shell Rimula R4L 15w40 10L; $59.95ea
15% off Valvoline Super Diesel 15w40 20L: $105.95ea
Also 15% off a number of Castrol Edge & Magnatec 5L varieties, 15% of Penrite HPR10 10L and smaller specials on other products.