A fuel additive is a substance that improves the performance and efficiency of the fuel used in your car. However, there are numerous different product names that describe the various kinds of fuel additives available in the market. Fuel system cleaners, engine oil additives, fuel stabilizers and octane boosters are amongst the most common synonyms for fuel additives. Fuel system cleaners optimize fuel system performance, engine oil additives improve oil's capabilities, fuel stabilizers preserve the quality of stored fuel while octane boosters raise fuel's octane level. Fuel additives offer a cost-effective method of mitigating various problems related to fuel quality and vehicle performance.