Technical modifications on certain elements improve exploitation features of four-stroke engines. Some of the exploitation features described in final work are: horsepower, engine capacity, torque, fuel and oil consumption. To increase engine efficiency and to improve exploitation features the modifications which are considered in final work are modifications on car intake system, camshaft, engine cooling system and modifications on exhaust system. With implementation of technical modifications on engine elements the most impact is on engine horsepower and fuel consumption. Increasing engine horsepower there is much easier to overcome resistance which appear while driving which have direct impact on reducing fuel consumption. The main purpose of final work is to explain how and to what extent will implementation of certain technical modifications affect on exploitation features of fourstroke engines. The main problem is that with irregular implementation of modifications the accuracy of entire system could be disturbed. To achieve positive effect on exploitation features the detailed research of how modifications of certain elements impact on entire system is needed.