My plane came with a Shadin, something I would never have bought BUT, now that I have it I am a believer. Extremely accurate as long as you remember to input your fuel amounts correctly. I mainly set my amount of fuel on board whenever I top off. I also give myself a fudge factor of 4 gals or so, just in case. When I fuel out of jerry cans I will amend my total fuel as I add fuel. I also have the Fuel Hawk plastic tube as a back up.