Always spent ASB true rewards on mobil MTA vouchers , could use them in all petrol stations. Effectively as good as cash as always need petrol. 

Just bought a bunch of Mobil vouchers via ASB true rewards ---they've dropped the MTA affiliation though,  and can now only be used at Mobil gas stations.

Only 2 mobil stations in tauranga that I know of , and none on my side of the bridge. 

Doh!