Actually Paul Walker was a race car driver and he always bragged about his driving skills during press for the Fast films. He talked a lot about how his grandfather raced cars for Ford back in the day — which essentially explained his passion for racing. In fact after he did The Skulls — Universal asked him what he wanted to do next and he came up with the idea of the undercover cop who infiltrates the illegal world of street racing in LA. That idea became the pitch for The Fast and the Furious.
Racing was a huge part of his life and Roger Rodas (the driver of the car that killed them) also shared that passion. They both formed a racing team which was active up until their deaths.
In terms of his acting skills — like most actors he was only as good as the material — but I will say that he was awesome in Running Scared and Hours. I think he was just beginning to find his groove and would’ve proved himself more than just the “pretty boy” if he had lived longer.