1980 my first (and light) motorbike I dont remember to well but think it was about : 2,50 NOK per L. (reason is it took 4 L and i could fill it up with a 10kr. If i dont remember to wrong)
now it is about 10.00 NOK per litre.
10.00kr = 1,4$
1 gallon = 3780 ml, or 3.8 L