Radio-controlled (or R/C) cars are usually categorized as either "toy" or "hobby" grade. Remote control vehicles are usually of one of two types: control of a vehicle by radio transmission or by a wire connecting between the transmitter and car. This article focuses on the radio-controlled vehicle category, both toy and hobby grades.Cars are powered by various sources. Electric cars are powered by small but powerful electric motors and rechargeable nickel-cadmium, nickel metal hydride, or lithium polymer cells. There are also brushed or brushless electric motors. Most fuel-powered models use glow plug engines, small internal combustion engines fueled by a special mixture of nitromethane, methanol, and oil (in most cases a blend of castor oil and synthetic oil). These are referred to as "nitro" cars. Recently, exceptionally large models have been introduced that are powered by small gasoline engines, similar to weedwhacker motors, which use a mix of oil and gasoline. Electric cars are generally considered easier for the novice to work with compared to fuel-driven models, but can be equally as complex at the higher budget and skill levels.In both of these categories, both on-road and off-road vehicles are available. Off-road models, which are built with fully-functional off-road suspensions, can be used on various types of terrain. In comparison, on-road cars, which generally have a limited or non-existent suspension, are strictly limited to smooth, paved surfaces.
Hobby-grade radio control
In recent years, hobby-grade "ready-to-run" (or "RTR") models have become available from every major manufacturer of radio-controlled cars, attracting many hobbyists who would otherwise have purchased a pre-assembled car (ARTR or Race-Roller). Vehicles of this type need little or no final assembly and in many cases, the bodies are shipped painted and trimmed, requiring little work from the owner before they can be used (other than purchasing and installing