So I did not have a chance to calculate the miles per gallon on my new yaris until today. Now most of this is high way driving coz Friday I had to make a round trip from Iowa City and Des Moines. But it’s not too bad at all

366.1 miles on 9.898 gallons = 36.99 miles per gallon

But understand that gas mileage does fluctuate up to a year on a new car.