(This article was written by Olivia Madiraca, Sunoco’s Manager of Race Fuels Development and Technical Support for publication on the Sports Car Club of America Website. Sunoco is the official fuel of the SCCA®.)
As winter approaches, car enthusiasts need to consider how to prepare their car for the off-season. One of the most important aspects of winter storage is properly readying the car’s fuel system for months of sitting stagnant. Many cars are stored outside at ambient temperatures and conditions, meaning they’re exposed to temperature changes, humidity, and moisture from rain and snow. As the gasoline sits in your car over winter, it will begin to degrade and age, the results of which are only exacerbated by the outdoor conditions. It’s also important to note that oxygenated fuels, such as fuels with ethanol, in a car for extended periods of time could lead to damage of gaskets and hoses in the fuel system.
If you just read that and thought: My competition vehicle is stored in the garage or trailer, so this is not my concern. We ask you: Is your tow vehicle treated as kindly? And even if your competition vehicle is under cover, it’s likely still experiencing temperature swings.
As a vehicle sits exposed to ambient conditions for an extended amount of time, several things happen to the fuel. The fuel will begin to degrade and oxidize; oxidation leads to gums and varnish formation and lowers the octane of the fuel. Gums and varnish will cause fouling and deposits in an engine, which upon starting in the spring, will lead to poorer engine performance. The aromatic molecules that make up gasoline have a lower octane number after oxidation; these aromatic molecules have the largest octane rating of all the components of gasoline, so their oxidation can have a big impact on octane...
Read the original article on the Sports Club of America Website