Using Old Gasoline in Modern Cars and Power Equipment

The question of whether old gasoline can still be used in modern vehicles and power equipment has been a topic of debate among mechanics, DIY enthusiasts, and homeowners alike. Here, we'll explore the considerations and best practices for using stored gasoline in your car, lawn mower, and boat.

Understanding Gasoline Degradation

Gasoline, particularly those with ethanol additives, can degrade over time. When stored improperly or for extended periods, it can lose quality and potentialy cause issues in your engine or other equipment. Understanding the degradation process is crucial in determining whether old gasoline is suitable for use.

Degradation: Gasoline can start to break down after about three to six months. During this process, the fuel begins to form gums and varnishes which can clog fuel filters and injectors. These particles are particularly problematic for older engines and fuel systems.

Odor and Appearance: Over time, stored gasoline can also change in appearance and smell. A sour smell or visible particulates can indicate that the gasoline has degraded and should not be used. Always check the gasoline for any signs of spoilage before considering its use.

Compatibility and Mixing

While modern vehicles often have more robust fuel systems that can handle some degree of contamination, it is wise to err on the side of caution, especially with old gasoline. Mixing old gasoline with fresh, high-quality fuel can help mitigate any issues that may arise from using the older product. However, if you're uncertain about the quality of the old gasoline, it's best to dispose of it properly.

Best Practice: If the gasoline appears and smells normal, and if your vehicle's fuel system is capable of handling it, mixing it with fresh gasoline can be a viable option. However, if you're unsure, consider taking it to a hazardous waste facility or a location that accepts old gasoline. This ensures that the environment is not affected and that any leftover gasoline is disposed of safely.

Real-World Examples

Several individuals have shared their experiences with using old gasoline in different contexts, providing both practical insights and cautionary tales. Here are some real-world scenarios:

Mowing Lawns and Snow Blowing: Users have reported using gasoline stored for over a year in their lawn mowers and snow blowers without issues. However, they do caution that the performance might not be optimal, and there could be a risk of filter or fuel injector clogs.

Boat Fuel Tanks: For boats with a full tank of non-ethanol gasoline, the situation is slightly different. A personal experience involving a 30-gallon inboard tank and a 90-horsepower Honda 4-cycle outboard engine demonstrates that even after three years with non-ethanol fuel treated with stabilizer, the boat engine ran perfectly well. This scenario highlights the importance of treating gasoline and maintaining a clean fuel system.

Engine Maintenace and Fuel System Care

To minimize the risk of issues with old gasoline, it's crucial to maintain proper fuel system care. This includes:

Regularly treating gasoline with stabilizers, especially if it is to be stored for long periods. Running the engine down to a quarter tank before refilling with fresh fuel in the off-season. Ensuring that fuel tanks and fuel lines are well-sealed and protected from heat and moisture. Using water separators and regular filter replacements to prevent water contamination in fuel.

By taking these precautions, you can reduce the risk of issues associated with using old gasoline in modern engines and equipment.

Conclusion

The decision to use old gasoline is not without risk, but with careful consideration and proper maintenance, it can be a viable option in certain situations. Always err on the side of caution and seek professional advice if you're unsure about the quality of the gasoline. Proper maintenance and care of your fuel system can significantly mitigate the potential risks associated with using stored gasoline.