How Many Gallons Do You Need For Every 150 Miles?

gallons of what?

You will need to know   m / gal    (mpg)    ....    then  150 / (mpg) = gallons needed

if you're talking about gas milage then it depends on a lot of things. the type of car, whether you're on the highway or driving through the city. as an example I will use a car that gets 20 mpg on the highway. that's 150 / 20 which is 7.5 so you'd need 7.5 gallons to travel 150 miles on the highway driving a car that gets 20 mpg.