Chevrolet Impala LTZ The 3.5L V6 engine is designed to deliver highway mileage the Ford Taurus, Dodge Charger and Nissan Maxima can't match - 29 MPG highway(7) when running on gasoline. Power and torque when you need it. Both the 3.5L V6 and the 3.9L V6(8) feature Variable Valve Timing(VVT). By adjusting the timing of the intake and exhaust valves, VVT optimizes combustion, enhances low-end torque and high-end power, and helps control emissions.