From the Super Mario Wiki
The Lightning Champ is Mario's kart that is found in Mario Kart Arcade GP DX. It is shaped like a Formula One Car, similar to the Sprinter from Mario Kart Wii and the Circuit Special form Mario Kart 8. It has a red body with blue stripes and white lines, like Mario's signature overall and cap color. Its alternate colors are red with a central white stripe and yellow with a black W-shaped mark and white on the sides. It offers a boost in speed performance while not hindering or improving anything else.