KARR ever threatened to use it to harm someone. KITT used this to rid the compartment of smoke after bombs were detonated in his trunk. Engine and driving KITT is powered by the Knight Industries turbojet engine, with modified afterburners. and a computer controlled 8-speed turbodrive transmission. This helps him do 0–60 mph in 2 seconds (1.37g), standing to quarter mile 4.286 seconds. Electromagnetic hyper-vacuum disc brakes: 14 foot (4.25 m) braking distance (70–0 mph – 112–0 km/h – 11.7g). KITT primarily uses hydrogen fuel. However, his complex fuel processor allows him to run on any combustible liquid, even regular gasoline. In one episode, KITT mentioned his fuel economy was at least 65 miles per gallon. However, when operating on fuels other than liquid hydrogen, KITT's fuel efficiency and power output may be lowered. Used in most episodes, KITT can employ a "turbo boost". This is a pair of rocket boosters mounted just behind the front tires. These lifted the car, allowing KITT to jump into the air and pass over obstacles in the road. Also, occasionally, Turbo Boost was used to allow KITT to accelerate to incredible speeds in excess of 200 mph (322 km/h). The boosters could fire forward or backward, although the backward booster was rarely used. In later seasons, a passive laser restraint system helped protect Michael and any passengers from the shock of sudden impacts and hard stopping. It is speculated that this is a primitive form of an inertial damping device. First used in Episode 47, "Knight of the Drones". KITT has four main driving modes: Normal cruise – On "Normal", Michael has control of the car. In an emergency, KITT can still take over and activate Auto Cruise mode. Auto cruise – KITT has an "Alpha Circuit" as part of his main control system, which allows the CPU to drive the car utilizing an advanced Auto Collision Avoidance system. KARR's Alpha Circuit was damaged due to being submerged in water for a time, which required him to have an operator to control his Turbo Boost function. Pursuit mode – "Pursuit" is used during high-speed driving and is a combination of manual and computer assisted operation. KITT could respond to road conditions faster than Michael's reflexes could; however, Michael was technically in control of the vehicle and KITT helped guide certain maneuvers. Silent mode – The feature dampens his engine noise and allows him