Use a coles express ATM and redeem 1, 5c/L voucher off your fuel, can be used in conjunction with an everyday discount docket. Current coles promotion is 8c/L so save 13c/L when used together.
Buy 1 get 1 free on V 4 packs at coles express. So 8 cans for $8.70, less than $1.10 a can. Seems like a good deal.