It is important to note that it is illegal to switch your car off while in traffic. Start stop vehicles are exempt to this due to the safety systems involved, ensuring that the vehicle will be able to restart and will do so immediately as you take your foot off the brake. Automatic cars are designed to be able to sit at idle and in gear. This ensures the transmission’s oil system is at full operation pressure and allows for instant movement when you need to accelerate. It’s advisable to let the engine revs on automatic cars stabilise before and after engaging another gear, prior to accelerating. If you are turning the car on and immediately changing gears, you are likely to prematurely wear your transmission.