The development of internal combustion engine encourages the development of what it uses in its work – the fuel. The research in the field of engine technology has direct impact on the production technology and fuel preparation. In order for both of these aspects to function as a whole, they need to be coordinated. Harmony of fuel and engine leads to maximum efficiency of their purpuse and function in all aspects relevant to vehicles and people. Of course, the search for perfection is constant, ie. for results which will satisfy as many demands as possible. The fuel is based on crude oil. It is an extremely important factor in the automotive and fuel industry, it could be – their link. However, oil itself is not sufficient. It needs to be processed in order to be used. The missing link without which its usage would be almost impossible are additives. Without them oil usage would be unprofitable, inefficient and would not comply with specific norms relating to the quality of fuel and protection of the environment. Due to the use of gasoline and diesel fuel as power source in vehicles, there are special kinds of additives for each of them. Some of them are very different while some are quite similar in composition, chemical and phsysical activity and adding limits. Each of them has a specific purpose to improve the property of the fuel, which makes them important for adjusting raw materials for effective and extremely widespread appliance.