A tuner car, often from Japanese, Asian or European manufacturers, is a car that combines comfort, practicality and high gas mileage with performance modifications, primarily to its engine. Tuners are normally good-handling vehicles, due to their light weight and more sophisticated suspensions.

Tuners are different from supercars in many respects, from price to engine displacement and horsepower. However, they're not the typical imported sedans or SUVs; they are lighter, faster and have better handling.

What distinguishes a tuner from the rest of the cars is that the owner is - in many ways -personalize the car to their liking. They are manufactured in a way that makes it easy for the owners to improve the cars. Some are even de-tuned to meet horsepower limits of other countries. Japan is a good example of this examples are the Skyline GTR and the Toyota Supra which both were held on paper to the 276 bhp limit which was agreed on all cars until January 2005, owners whom bought the cars new placed them on a dyno and were running close to 330 bhp and even that is a detuned state with true running on there stock internals close to 600 bhp and with further mods able to see well over 1000 bhp. What makes tuner cars popular is simple mods show a lot of results against a non tuner car.

Modifications range from visual upgrades such as changing the rims, tinting the windows and installing bodykits, to a variety of performance modifications (primarily to the engine), such as installing a short shifter and a Weighted Gear Knob, depending on what the car is "tuned" or set up for. Often bodykits are fitted due to being lighter or offer more air flow and can be a mix of carbon fibre. In the drift scene aftermarket bumpers are fitted due to there bangs they can easily be refitted or replaced even more so as some are road legal and when car test day arrives stock parts have to be fitted so it is easier to save the stock bumper for those days.

But be aware of many tuner cars hate to see a mass of over the top mods which serve no purpose, this can differ from Modded cars where not always but often it is a style upgrade against a tuner car which will more often have parts related to it use may it be track to drag and drift. This has often been a common mix up from modders to tuners which are often classed the same but although some due mix the scenes, the truth is they are different. But you will see a mix of pro Tuners like big brand parts makers and sellers like Topsecret, Trial, HKS, Sumo, Jun to name a few to the street tuners. Again not to be mixed with modders.

Tuner engines are also a popular option for modders, popular conversions are the Nissan RB and SR series of engines as well as Toyota JZ engines. More recent V8 engines are being used from cars made around the World. And European performance engines.

Some tuner manufacturers offer variants of their cars with performance modifications already installed, such as the Subaru Impreza STi and the Mitsubishi Lancer Evolution. Due to their smaller engines, these cars are often manufactured with turbochargers and superchargers in order to compete with other sports cars.

A Tuner also can refer to the driver of a tuner car.