I was curious about the optimal use of the AA card for fuel savings at Caltex.
The following table takes assumes $2.10/L and a 6c/$40 discount accumulated (being an AA member):
- 19.04L x $2.10 = $40
- 50L x $1.98 = $99
total - $139 for $69.04L -> 2.01/L
- 38.08L x $2.10 = $79.96
- 50L x $1.92 = $96
total - $175.96 for $88.08l -> 1.99/L
- 76.16L x $2.10 = $159.93
- 50L x $1.8 = $90
total - $249 for 126.16L -> 1.97/L
- 190L x $2.10 = $399
- 50L x $1.44 = $72
total - $471 for 240L -> 1.96/L
- 380L x $2.10 = $799.68
- 50L x $0.84 = $42
total $841.68 pt. 430L -> 1.95/L
- 647L x $2.10 = $1359
- 50L x $0 = $0
total $1359 for 697L -> 1.94/L
It seems that the 50L limit is intentionally set so low (compared to the 150L on supermarket vouchers).
Conclusion? The easiest way is to put $40 worth of fuel and then put 50 more liters (assuming you have a large enough tank) which is the way I've been doing it.
It is slightly more economical to put a few more $40 but it may not worth the hassle and the points do expire after the end of the second month if I recall correctly.
Hope this helps someone.