How the engine is used, is key to selecting the right oil for that specific use. A car that is used only for daily use needs a higher Total Base Number (TBN: it measures how much acid neutralizing power is in the oil) than a race car that runs 50 laps. You may not believe it, but corrosive wear is one of the major forms of wear in your engine. In fact, one of the major reasons for a longer engine life today is found in minimizing corrosive wear.
Driving your car for a short distance is the worst for producing engine-killing acids. Water is a side product of fuel combustion. What happens is that some water condenses and gets into the crankcase of your engine. If the engine does not get warm enough to allow the water to evaporate out of the engine, the water builds up. When the engine is turned off and is cooling down, the water vapor will condense and you will get water in your engine. The water will mix with the sulphur oxides present from the combustion process in the oil and the partially burnt fuel to create a very corrosive chemical mix.
Racing oils are formulated for tough, high-temperature operation. This requires a high-quality oil with an additive package that provides high wear and oxidation resistance compared to everyday motor oil. Base oils make up 80% of the finished product in the can that we buy. The rest are various additives. A high-quality base oil usually requires less additives to achieve good performance, while lower quality oils need a better additive package.
To overcome the previously mentioned corrosion problem, oil engineers have developed special additives to fight this. Because a race car engine is working much harder than a normal engine there are also different requirements where in protection against corrosion is not the biggest worry. Normally the oil engineers add special anti-wear additives which will act as a wear protecting shield for your engine parts.
