Thanks to the most recent technology, fully electric vehicles are becoming reality. Everything is going to move towards electric transportation, but combustion engines are still one of the most widely used technologies, not only in automotive industry. Probably, in the future, a perfect combination of them will be the right step before a complete transition to electric vehicle but in the meantime, it is essential to continue working to make engines more efficient, in terms of fuel consumption, performance and emissions. Emissions are probably one of the biggest challenges for car manufacturers, who equip vehicles with complex but efficient exhaust systems to reduce pollutants, making exhaust system design a critical point in the vehicle engineering process.