Berg is spot on. I never lock the handle and I put my ear to the fill cap and listen for when it starts to get full. Then I slow down so I can get as much fuel in as I can. If it starts to slosh, an air pocket can get hung in there and the tank won't get completely full. I think I average about 4 to 5 gph and I ski, surf, and wakeboard with anywhee from no ballast to about 1500 pounds for surfing. 8 gph is a lot for an outback.