We’ve all seen the scene in The Fast and Furious where Brian O’Connor just lost his first race to Dom. Yet he is standing next to the car with a gigantic shit eating grin on his face. “I almost had you man!” Which incites laughter and mockery from street racing legend Dom. “Granny-Shifting. Not double-clutching like you should.” This has always been one of those famously cringe worthy quotes. In case you’re unfamiliar with the concept of double clutching the concept is simple. When executing a shift you follow these steps. #1, lift off the accelerator. #2, Depress the clutch pedal. #3, Shift out of gear into neutral. #4, Lift off the clutch pedal. #5, Re-depress the clutch pedal. #6, Shift into the desired gear, rev matching where necessary. #7, Release the clutch pedal. It is worth noting that this is a fluid process, many of the steps are happening together to form a seamless, smooth shift.
So why is this cringe worthy? Well, as any car guy will tell you modern cars have transmissions with synchros. Synchros make shifting much easier and much smoother. It allows for seamless meshing between the gears with reduced risk of grinding them. In the old days, the days before synchros you had to double clutch. So, and I hate to disagree with the all-knowing Dominic Toretto but your burn is incorrect. The glorious ignorant newb you will later call Mr. Arizona was correct in his chosen style of shifting.
So, just to be clear… If your car has a manual transmission in perfect working condition there is absolutely no need to double clutch.
In any rate if you are still unclear on the concept or just want to geek out on transmission tech talk watch the following video. The entire concept is explained by someone far smarter than I am.
Source: Engineering Explained on YouTube