It depends. In the past the answer was probably not. In today's regulatory climate they play an important role for the average motorist. Past turbos were designed with sheer power in mind. Today's turbos are designed to enable small displacement engines to comfortably haul around 3,000 lb vehicles. The base 1.4 liter engine in the 1st generation Cruze can only output 86 HP. This is more than sufficient to keep the car moving on level ground (it takes about 15-17 HP to keep my ECO MT cruising 65 MPH on the highway), but it's way too little power to accelerate at a reasonable speed or climb. Larger engines don't need a turbo for this but they consume more fuel, lowering their fuel economy and raising their emissions than a smaller engine with integrated turbo.