* Temperature: Diesel fuel is most stable at temperatures between 40 and 80 degrees Fahrenheit. When diesel fuel is exposed to higher temperatures, it can start to break down and form gums and varnishes. These can clog fuel lines and injectors, causing engine damage.
* Light: Diesel fuel is also sensitive to light. When exposed to light, diesel fuel can start to oxidize and form peroxides. These can cause engine damage if they are allowed to build up.
* Air exposure: Diesel fuel should not be exposed to air, as this can cause it to start to oxidize and form gums and varnishes.
If diesel fuel is stored properly, it can last for up to two years. However, it is important to note that diesel fuel that is two years old may not perform as well as fresh diesel fuel. It may have lost some of its volatility, and it may also contain more gums and varnishes. This can cause problems with engine performance and fuel efficiency.
If you are using diesel fuel that is two years old, it is important to take precautions to prevent engine damage. You should:
* Use a fuel stabilizer. A fuel stabilizer can help to slow down the degradation of diesel fuel.
* Change the fuel filter regularly. The fuel filter can help to remove gums and varnishes from the fuel.
* Run the engine at a high speed for a few minutes before putting it under load. This can help to clean out the fuel system and remove any deposits that have formed.
If you have any concerns about using diesel fuel that is two years old, you should contact a qualified mechanic.
