In today's world, where the need to protect the environment is increasingly emphasized, the emissions and fuel consumption of cars represent a major impact on the environment. This paper investigates the relationships between emissions and fuel consumption in different car types and driving cycles. The simulation of harmful gas emissions and fuel consumption was carried out using the ADVISOR program on two drive cycles. A comparison of fuel consumption and emissions of harmful gases was made for cars with diesel, gasoline and hybrid drive, as well as the influence of engine heating on consumption and emissions. The obtained results showed that the diesel-powered car has the lowest consumption, the hybrid-powered car has the lowest emissions in city driving, while the emission results on the intercity section are uniform. The diesel engine has the highest emissions of harmful gases in the city section and significantly higher emissions of nitrogen oxides compared to gasoline and hybrid engines. The heating of the engine and the catalyst, which becomes effective only after reaching the operating temperature, has a very large influence on the emissions of harmful gases.