Adding a high accuracy fuel flow meter onto your boat is a much easier installation then most people would assume, and it gives you some important advantages. Let’s face facts: just about anyone who’s run a boat for years on end has either run the fuel tanks dry, or come close enough that they’ve stressed over reaching the dock. A flow meter takes care of these concerns, and tells you when you need to turn around and head for home, plan to fuel up for the next trip, or even if you need to slow down to conserve fuel, because you risk running out.
Of course, accuracy is important, and all flow meters are not created equal. Modern outboards which compute fuel flow via their onboard brains are great, but if your engine doesn’t have this feature built in the chances are, you need to add a mechanical meter. One simple rule of thumb will help you pick out one that’s reliable: if a fuel flow meter costs less then $350, you can pretty much bet it’s quality leaves something to be desired. And that’s just the meter; plan on spending more for the display, if the meter you choose won’t play nice with a display that’s already at your dash.
You want some specifics? Fine. I’ll speak to two fuel flow meters which I’ve had in my own boats, and can vouch for when it comes to accuracy: FlowScan and Yamaha. In my experience the FlowScans reliably run within two percent of actual burn. The Yamahas reliably run within five percent of actual burn, but do better if you don’t troll very much because their reliability is better at high flow rates then it is at low flow rates. One key factor: it’s important to make sure the flow meter is installed in a lever, secure position, without any kinks or sharp bends in the line prior to the meter. These cause turbulence in the fuel flow, and when air bubbles hit the meter’s paddlewheel, they throw the readings off.
You want to extend your range, and end the uncertainty? Then add a fuel flow meter that has high accuracy – and of course, always keep 10 percent of your fuel supply in reserve!