No, not all Tesla models have a single motor per wheel. Tesla Model S and Model 3 typically come with either one motor (rear-wheel drive) or two motors (dual motor all-wheel drive). However, the new Tesla Roadster and Tesla Cybertruck are equipped with a tri-motor setup, one for each rear wheel and one for both front wheels. The Tesla Model S Plaid also has a three motor system. None of them, however, have a distinct motor for each wheel. The purpose of having these multiple motors is to provide better handling, traction, and acceleration performance. It's important to note that specific configurations may vary based on the model and options selected upon purchasing.