What is it about people and petrol prices? … OK …not all people!
However, It does qualify as a “Barbecue Stopper” (Thanks Fiona Katauskas … and Tony Abbott?) when the petrol price suddenly rises or falls, its in the news and people talk. It can start up some irrational behaviour. I did know a bloke who would fill up jerrycans of petrol on any fuel price reduction.
Slack Investor has been guilty of it himself … driving across town to save 4c per litre … and perhaps using the amount of fuel that I am supposedly saving! Fuel prices are important to Australians as only a few Australian cities have great public transport networks – and the car is a necessary evil, and petrol is a non-discretionary expense, in a lot of cases.
WISH cards are gift cards that can be purchased at a 5% discount at a variety of places I get mine through RACQ, a local motoring organisation that has member discounts. You 
apply online and you can get a physical WISH card or an e-gift card number that you can use straight away at any Woolworths aligned store or petrol station.
5% discount doesn’t sound like much – Why would you bother? – I would usually agree, but, if there is no inconvenience to using the card, Why Not!
Let me give you an example. My current cost for petrol is $1.44 per litre, using the e-gift card (which I buy $500 lots and hide in my car! …I admit, there is some risk here … but so far so good!). The 5% discount is a saving of over 7c per litre – which can be added to any other loyalty discount (usually 4c per litre).
Now, Slack Investor does not want to create the impression that he is excessively frugal – I enjoy spending money on things that I like e.g., travel. However, all day to day expenses should be examined in a rational way so that you can then use any savings to do the things you enjoy – or, to increment your way towards financial independence.
I like your way of doing this Slack Investor, nice job! May have to try that trick ourselves.
Tristan