The "GTO" in Pontiac GTO stands for "gran turismo omologato," which is an Italian term indicating a car is built to specifications can be driven in competitive racing. According to The Huffington Post, former General Motors executive John DeLorean named the car in homage to a Ferrari model.
The Pontiac GTO debuted in 1964. To create it, GM swapped out a 326-cubic-inch engine in a car it was developing with a significantly more powerful 389-cubic-inch engine, according to The Huffington Post. The large engine in a relatively lightweight car gave the GTO impressive power and resulted in the beginning of the muscle car era in the American auto industry.