A turbocharger is a forced-induction system that increases engine power by using exhaust gases to spin a turbine, which in turn compresses incoming air and forces it into the engine to create more powerful combustion. Unlike a supercharger, a turbo does not draw power directly from the crankshaft, making it generally more efficient, but it can experience “turbo lag” as it relies on exhaust flow to build boost pressure. Turbochargers allow smaller engines to produce the power of larger ones while maintaining better fuel economy, which is why many modern vehicles, such as the BMW 330i, use turbocharged engines. Proper tuning and supporting components are important to maintain reliability under increased boost pressure.