You can typically cover a 40 ft. RV with 8oz of F11. Use half trigger pulls as you apply, less is more with F11 so a little goes a long way. One half trigger pull spray will cover a large area, there's no need to spray every square inch. Your application towel will become wet with the product and turn into a wet wipe where you don't have to spray as much going forward. Most of our RV or boat owners however, purchase the gallon size so they can do multiple coats. See all of our products at https://topcoatproducts.com/.