Electronic devices consisting of hardware and software for downloading and uploading information, files and data to and from land vehicles for increasing or adjusting engine performance, horsepower, and for engine diagnostics; downloadable operating system software updates for the foregoing; handheld and mountable electronic devices with displays for use in connection with land vehicles to assess, monitor and record engine performance, horsepower, and engine diagnostics; downloadable electronic publications in the nature of text files and electronic manuals for use by professional and amateur auto mechanics in the installation, maintenance and troubleshooting of the foregoing electronic devices; downloadable operating system software updates for handheld and mountable electronic devices with displays for use in connection with land vehicles to assess, monitor and record engine performance, horsepower, and engine diagnostics; gauges for land vehicles, namely, automotive gauges in the nature of water temperature gauges, boost gauges, vacuum gauges, and exhaust gas temperature gauges; computer application software for mobile phones, namely, software that allows a person to limit the top speed and acceleration rate of a vehicle to promote safe driving; and computer hardware for vehicles which interacts with computer application software for mobile phones, namely, software that allows a person to limit the top speed and acceleration rate of a vehicle to promote safe driving; electronic automotive tuning device, namely, electronic control hardware unit which interfaces with a vehicle's drive-train computer system and reprograms the vehicle's microchip to make it go faster, have more power, get better gas mileage, and enhance the performance of the vehicle, with user control and interaction through a program running on a smart-phone or other hand-held interactive media player, that communicates with the device through telecommunications equipment; electronic devices consisting of hardware and software for downloading and uploading information, files and data to and from power sports vehicles, namely, snowmobiles, utility vehicles, all-terrain vehicles, motorcycles and watercrafts for increasing or adjusting engine performance, horsepower, and for engine diagnostics; handheld and mountable electronic devices with displays for use in connection with power sports vehicles to assess, monitor and record engine performance, horsepower, and engine diagnostics; downloadable electronic publications in the nature of text files and electronic manuals for use by professional and amateur power sports mechanics in the installation, maintenance and troubleshooting of the foregoing electronic devices; downloadable operating system software updates for handheld and mountable electronic devices with displays for use in connection with power sports vehicles to assess, monitor and record engine performance, horsepower, engine parameters and engine diagnostics; gauges for power sports vehicles, namely, gauges in the nature of water temperature gauges, boost gauges, vacuum gauges, air fuel ratio gauges and exhaust gas temperature gauges