When to Use Marine Fuel Stabilizer 

Some boaters might think using marine fuel stabilizer is a waste of time and money. Is it a useless product or simply a marketing gimmick? We don’t think so.

We sell fuel stabilizers here at Boats.net, so of course we’re going to sing its praises, right? Well, yeah. We make our living selling boat parts and products. But we don’t want you to buy anything you don’t need either because we’re also about saving you money (hence our slogan, “The Alternative to Retail Prices”). So with that in mind, here’s a quick guide for when to use marine fuel stabilizer.

For Ethanol Fuel

Fuel stabilizers help prevent water intrusion. And if you use your boat every week, its outboard motor will burn through the fuel before it gets a chance to absorb much water, so using a fuel stabilizer isn’t necessary at every fill-up. 

However, if your outboard doesn’t get much use, you should add fuel stabilizer to the tank. Ethanol fuel attracts water, which can cut the fuel’s combustibility. Marine-specific fuel stabilizers slow the rate of water absorption by the fuel and reduce the chances of phase separation. 

For Marine Fuel

Marine fuel doesn’t absorb water, but like any fuel, it has a limited lifespan before it goes bad. This degradation can begin within 30 days of the fuel being added to the boat’s fuel tank. As with ethanol fuel, if you frequently use the outboard, it’ll consume the fuel before it can go bad, so a fuel stabilizer isn’t necessary when refueling in this case.

However, if you aren’t getting through the entire fuel tank at least once a month, adding fuel stabilizer to regular marine fuel prevents it from breaking down within your outboard’s fuel system, keeping the fuel fresh for as long as possible.

For Winterization

Whether you fill your tank with marine fuel or ethanol fuel before winterization, always add fuel stabilizer and run the outboard for a couple of minutes. This draws the stabilized fuel into the fuel system, and prevents it from oxidizing or leaving deposits within carburetors or fuel injectors. When winterizing your outboard, protecting the fuel system with fuel stabilizer is probably the most important step you can take.

There are plenty of marine fuel stabilizers available, from Mercury QuickStor to Yamalube to Gold Eagle Sta-Bil, to name a few. Read your outboard’s owner’s manual for the manufacturer’s recommendations, plus the information on the fuel stabilizer’s label to determine which product suits your motor best.