At some point The Fast and the Furious franchise hit a dead road with "Tokyo Drift" in 2006. Three years later they tried to revitalize the franchise with "Fast & Furious," a step in the right direction, but that still failed in my books. So four F&F films and four duds, in my opinion. Then the strangest thing happened: "Fast Five." The Rio location worked. The addition of The Rock did wonders to spark the franchise. Diesel looked rejuvenated. I actually like a film from this god forsaken franchise. That was it for me as far as these movies go and the two that followed "The Fast and the Furious 6" and "Furious 7" were well-met, but I thought they were just fine. Anyway, these films really seem to strike a chord with high-schoolers. They love cars. They love skimpy chicks. They love Vin Diesel, who happens to be highest paid actor in Hollywood alongside, guess who, The Rock. These films are cash cows.
Don't forget, they eventually have to go to space.