With petrol prices what they are at the moment, and needing to fill the Pony with 98, I've changed the way I buy fuel.
Rather than waiting till I'm near empty, and maybe being forced to go to a nearby petrol station where prices are high, I now do the following...
On my daily travels, which is never the same route or area twice due to the kind of work I do, if I have half or maybe two thirds of a tank left, but happen to pass by a station with highly discounted 98, I'll top up the tank.
More effort I know, filling multiple times, but the end result is I save $$$ at the end of each week.
Even saving $10 a week doing this is still an extra $520 in my wallet each year.
I also use the PetrolSpy app, but this saves driving out of my way just to fill up at the best price.