Turbochargers increase engine efficiency by forcing more air into the engine cylinders for combustion. They work by using the engine's exhaust gases to power a turbine, which spins a compressor wheel to compress and feed ambient air into the engine at high pressure. Turbocharging can increase engine output by up to four times and significantly boosts power while lowering emissions and fuel consumption. It works by extracting energy from the exhaust gases that would otherwise be wasted.