Just for the record, one US gallon = 4 quarts and 1 quart = 0.946 Liters. So

($1.90 NZD/Liter) x (0.946 Liter/quart) x (4 qt/gallon) = $7.19 NZD/US gallon

but I do not know the exchange rate for $NZD to $USD.

Don Shillady
Retired Scientist/teen rodder