Jase2985:

you missed the point. to amass say a 30c saving you have to go to the petrol station 6 times (5 to accumulate and 1 to use it say) thats 2x as many fuel ups as you would need if you just filled it up 3 times over the same period/distance. does the meagre amount you save between the 2 fuel ups using your 6c per L vs the 6 fuel ups 5 @ \$40 and 1 full tank make it worth your time of having to A. potentially go out of your way to find a station, and B. spend the extra 3 amounts of time fueling up at say 5 minutes a fuel up (15 minutes minimum)

3 tanks at 50L = \$300 (fuel at \$2/L) less \$.06/L = \$291

5 tanks at 20L = \$200 (fuel at \$2/L) + 1 tank at 50L = \$100 less \$0.30/L = \$85 total = \$285

difference = \$6 or average \$2 per extra fuel up or \$1 for each fuel up.

for me the savings isnt worth the hassle given I would be filling up every week as opposed to every almost 3 weeks.

it may work for some but for others the merge savings just isnt worth is

You don't need to leave the petrol station between putting fuel in your car though. You can do 3 'fills' (at least, maybe more) at a pump before you need to go into the shop to pay. Select \$40 on the pump, put fuel in your car, replace the handle, wait a few seconds and do the same again.

You missed out a 6th discount in your calculation when you put in 50L so the actual price would be \$282 instead of \$285 making a \$9 saving for the same amount of visits to the petrol station, you just need to reset the pump at \$40 which adds a bit of time between each 'fill'.

By playing the system to my best advantage I turn a 10c/L discount into 26c/L, giving me an overall 12.5% discount on my fuel costs. This has only been when I have travelled a lot over a few months, but the principle is the same, just to a slightly lesser extent, but the longer you accumulate \$40 'fills' the better the overall discount will be.

You use so little fuel that I can see it's probably not worth it for you. I've saved over \$1000 by doing it the way I do and am happy to spend an extra minute or two in the petrol station each time I go to do get that.