An "aftermarket tuner" refers to a device or equipment that is added to a vehicle after it has been manufactured, to enhance its performance, power, or customize it according to the owner's preferences. Full definition
Factory tuned for more power, snappier shifting, and greater handling, the Civic Si has long been a favorite of aftermarket tuners seeking to extract even more performance from the car's naturally aspirated 4 - cylinder engines. (nydailynews.com)
Lotus Motorsport lured many owners into its parts catalogue; many others were enticed by offerings from aftermarket tuners. (evo.co.uk)
The Friedrichshafen, Germany - based aftermarket tuner's latest creation is a pint - sized Italian stallion with a carbon - fiber wide - body kit. (automobilemag.com)