Winter Storage: Is Your Fuel System Ready?


Winter Storage: Is Your Fuel System Ready?


Winter and hot-rodded cars generally don’t mix well. Oh sure, some of you gladly drive your old machine through the deepest, coldest parts of the season, gleefully getting sideways in the cold slushy stuff at every chance possible. But if you have a choice, most of you would rather see the object of your skinned knuckles and spent dollars waiting out the cold parts of the year in a nice, safe garage.

And that makes a lot of sense. Old cars are often balky in cold weather. And even if you do want to put up with the difficult cold-blooded start and long warmup a typical vintage car needs in the winter, there’s still the risk of going out and wrecking it on slippery streets, not to mention the potential for accumulating rust-inducing salt in many parts of the country.

But while it’s generally acknowledged that parking your ride in the winter is the best way to preserve it over the long haul, you have to do it the right way. In particular, your car’s fuel system is especially vulnerable to the effects of not taking the proper precautions when storing a vehicle. The consequences of a poorly prepared fuel system sitting for four to six months of winter can be frustrating. At the very least, you could have difficulty starting the vehicle in the Spring – while your friends are jumping into their cars and cruising the first warm day of the year, you’ll be stuck in the garage inventing new swear words for the phenomenon of Cruisis Interruptus.

Worse yet, not preparing your fuel system properly can cost you some pretty substantial bucks too. Any part of the car that fuel touches can be damaged by improperly storing your vehicle. That can include your fuel tank, fuel lines, fuel pump, and carburetor.

Not paying attention to fuel system prep before storing your car can bring on significant amounts of pain and aggravation, not to mention expense. At the very least, you'll be stuck sorting through messed up fuel components while your buddies are out having fun on the streets come Springtime.

The Poison in Your Tank

Most car owners run pump gas. And it can be a big problem when it comes to storing your car for the winter. That’s not to say pump gas is unacceptable for a performance car – it’s okay for the most part, especially when you consider the inconvenience, high cost, and sketchy legality of fueling a street-driven car with purer alternatives sold by the drum from racing fuel manufacturers. Fuel system components are now designed around the reality of running ethanol-blend fuels, so these parts can routinely handle them without issues. At this point, pump gas only becomes a huge issue when it degrades. The fuel you get from your local gas station contains many things besides gasoline. Even the best pump gas typically contains loads of additives, with ethanol being the most prevalent of them.

In time, these additives degrade as they’re exposed to oxygen and moisture in the air. Even worse, ethanol is hygroscopic – the technical term for something that attracts and absorbs water. When that concentration of water gets high enough, it settles to the bottom in the form of a whitish sludge. And since this slurry of water and ethanol ends up at the lowest point of the fuel tank, it's the first thing your carburetor or fuel-injection system will gulp in when you try to start it in the Springtime.

Adding to the problem, gasoline and ethanol tend to evaporate faster than chemical additives in fuel, which raises the relative concentration of them over time. These additives can accumulate as white, chalky deposits in your fuel system, carburetor, or fuel-injection unit, creating a range of vexing problems.

Fortunately, there are some proven steps you can take to limit the issues you’ll encounter.

Instead of nice, clean fuel system components like these, additives in fuel can leave behind heavy deposits of chalky white contaminants. At the same time, untreated fuel can degrade and leave gum and varnish inside your carburetor or fuel-injection system, forcing you to do an unplanned rebuild.

Don’t Empty the Tank

There is a long-running debate on whether or not you should drain your fuel system before storing your car. The argument can be made for doing so – without any fuel in the system, there theoretically isn’t anything to damage the system.

But, according to many experts, that theory quickly falls apart in practice. When you drain your fuel system, it’s impossible to get it completely dry and devoid of fuel. This means the potential for gum and varnish buildup remains – it only takes a light coating of fuel on the surface of parts to do so. Along with this, draining all the gas leaves sensitive rubber and plastic fuel-system components exposed to air, which they weren’t engineered to do. Instead, they were built to be always submerged in fuel. Leaving them exposed to air makes them prone to cracking and disintegrating.

Worst of all, an empty fuel tank leaves more room for moisture-filled air in it. Over time this moisture will combine with any remaining fuel – remember how ethanol loves to attract water? That means even more opportunity for that slurry of water and ethanol to form.

Fill It Up

So, before you store your car, you should fill the tank all the way up with fresh gasoline that has the lowest ethanol content you can get – preferably zero ethanol. Although it’s getting hard to find pump gas without ethanol, there are still some places that sell it. The website lists locations in the U.S. and Canada where you can get it.

And if you're running E85 in your vehicle, avoid leaving it in the tank all winter. Although E85 can be a wonderful fuel for making big horsepower, its high ethanol content becomes a liability when putting a vehicle away for months at a time. The amount of ethanol in pump E85 can legally vary from 51% to 83%. And that’s just begging for trouble in a vehicle that isn't being driven regularly.

If your car is worth all the effort you put into it, it's worth protecting it over the winter. It only takes a few minutes and a little forethought to make sure your fuel system gets the treatment it deserves before being put away for the season. Doing so costs pennies compared to the expense of fixing damaged parts later.

Add Fuel Stabilizer

Along with filling your tank all the way up before putting your car or truck away for the season, you should also add the recommended amount of fuel stabilizer. These proven additives can prevent gasoline from oxidizing and reduce water accumulation. At the same time, they slow the rate of degradation of fuel, so it remains viable enough to run when you’re ready to pull your car out in the Spring.

That said, there are a wide range of different fuel stabilizers on the market today. While it’s not our place to recommend one type over another, here are some key criteria to consider when choosing a particular brand or formulation:

Alcohol Content

Many fuel stabilizers contain alcohol, and just like in the fuel itself, this can cause problems. So look for a brand that doesn’t have alcohol.

Duration of Protection

Some stabilizers are formulated to protect longer than others. While pretty much all of them will go enough months to last through a winter, longer storage may require a different type of fuel stabilizer.


The specific concentration of different fuel stabilizers varies quite a bit. Make sure you read the label before adding it to your fuel system, to ensure you get the proper amount.

No matter what fuel stabilizer you choose, they’re all simple to use: Just follow the directions on the bottle, adding the recommended amount to a full tank of fuel before putting your car away in the winter. Then run the engine for at least 10 minutes to ensure that the stabilizer is distributed throughout the entire fuel system.

However, it’s important to note that no stabilizer can actually improve gasoline – all they can do at best is slow the rate of degradation. They can’t make old fuel fresh again. For that reason, you should add stabilizer immediately after filling up with fresh gas.

Then, when you pull your car out of storage, add fresh gas as soon as possible. It isn't a bad idea to drain your tank completely and refill it with fresh fuel before starting for the first time after storage, even if you did add the right amount of stabilizer in the Fall. Of course, that can be a pretty big hassle, and it’s not absolutely necessary. Instead, you can just run the old stabilized fuel and top it off as you go – don’t wait until your tank is empty to fill up with fresh gas. Instead, add fresh fuel at intervals, to raise the concentration of new gas as quickly as possible.

Follow these steps and you can prevent costly, frustrating damage to your fuel system, allowing you to reap the benefits of storing your car for the winter without the potential downsides. Doing so allows you to get out cruising instead of cursing when the first warm rays of Spring shine down upon your garage.

Click Here now to see Holley's full line of fuel system components for stock and modified vehicles!


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