EPA mileage is 19 mpg city, and 30 mpg highway. Expect about 24 to 26 mpg overall. General Motors also has used this basic platform with its Buick and Pontiac marque vehicles. When I got into the Regal, I noticed a boost pressure reading on the dash instruments. On the freeway I punched the throttle and the car literally leapt from 60 mph to a number on which I must take the Fifth.
Acceleration is to die for.
With or without a supercharger, this is a surprisingly good car, with ride, handling, and braking similar to the Intrigue and the Camry. If you are power hungry, the supercharged Regal GS is the car to buy. Given the choice, I would choose the slightly tauter Camry over the Regal, but perhaps not over the Oldsmobile Intrigue. Toyota Camrys have legendary staying power, with many accomplishing more than 200,000 miles with little in the way of repairs. Only time will tell with these new GM products.