Car tuning is the modification of the performance or appearance of a vehicle. For actual "tuning" in the sense of automobiles or vehicles, see engine tuning. Most vehicles leave the factory set up for an average driver's expectations and conditions. Tuning, on the other hand, has become a way to personalize the characteristics of a vehicle to the owner's preference. Cars may be altered to provide better fuel economy, produce more power, or provide better handling and driving.