1 Based on 2023 EPA mileage ratings for Civic, and 2024 EPA mileage ratings for Impreza. Use for comparison purposes only. Your mileage will vary depending on how you drive and maintain your vehicle, driving conditions and other factors. 2 ACC cannot detect all objects ahead and may not detect a given object; accuracy will vary based on weather, speed and other factors. ACC should not be used in heavy traffic, poor weather or on winding roads. ACC only includes a limited braking function. Driver remains responsible for slowing or stopping the vehicle to avoid a collision.