Some car parts that increase performance include superchargers, cold air intake kits, aftermarket air filters and performance chips. In an ideal scenario, a bolt-on supercharger increases the horsepower of a car by approximately 50 percent. A basic bolt-on supercharger can cost between $1,800 and $2,800, as of 2014.
In order to improve how much horsepower an engine produces, performance parts work to help the engine more powerfully or more efficiently combust fuel. A supercharger increases horsepower by compressing air before it reaches the engine, which allows the engine to accept more fuel. On cars with small engines, a supercharger can increase the efficiency of the engine, according to the U.S. Department of Energy.
Installing an aftermarket air filter allows the engine to accept more air and blocks impurities from entering the engine that can degrade performance over time. Unlike the standard air filter in a car, many high-quality air filters can be cleaned, which increases the lifespan of the filter.
A cold air intake improves performance and engine efficiency by feeding the engine cold air, which is denser than warm air and contains more oxygen. A cold air intake doesn't store the air filter in a box and increases air flow, further improving performance.
Newer model cars use a onboard computer to regulate how much air and fuel the engine uses. Installing a performance chip changes how much air and fuel the car accepts and can be used to improve gas mileage or horsepower.