As Zak mentioned it does happen to some degree in the Euro market. There's little difference (sometimes only ECU configuration) between some of the high end and

As Zak mentioned it does happen to some degree in the Euro market. There's little difference (sometimes only ECU configuration) between some of the high end and performance Volvos. It is a difficult thing to do though because high performance parts often come at the cost of price, fuel economy, reliability and usability. Using the performance variant turbocharger across a line of cars and setting the ECU to a lower boost would result in the lower spec ones having overly expensive parts that boost at the wrong rev range resulting in worse fuel economy and engine response.