Should You Shift to Neutral (N) at Traffic Lights with a Dry Dual-Clutch Transmission?
4 Answers
When waiting at traffic lights with a dry dual-clutch transmission, there's no need to shift to Neutral (N) for short stops. However, for stops exceeding 5 minutes, it is recommended to shift to N. Working Principle of Dry Dual-Clutch Transmission: The dual-clutch consists of three similarly sized clutch discs coaxially stacked together. The two outer clutch discs are connected to gears 1, 3, 5, 7 and 2, 4, 6, reverse respectively. The middle disc moves between them, engaging or disengaging with the two clutch discs to shift gears. Neutral (N) Gear: This is one of the three standard gears in automatic transmission vehicles, located between the R (Reverse) and D (Drive) gears on the gear shift console. Essentially, it represents the neutral position in the transmission, designed to disconnect power transmission between the input and output shafts within the gearbox.
From a mechanical perspective, I believe it's more reliable to shift to N (Neutral) gear when waiting at a long red light. In a dry dual-clutch transmission, when you keep the brake pedal pressed in D (Drive) gear, the clutch plates are actually in a semi-engaged state, similar to partially depressing the clutch in a manual transmission vehicle. Maintaining this condition for extended periods can easily lead to clutch overheating, especially during summer traffic jams. Personally, I shift to N gear whenever I encounter a red light longer than 30 seconds – this completely disengages the clutch, effectively giving the transmission a break. When the light turns green, shifting back to D gear causes minimal wear that's well within acceptable limits. Additionally, remember to engage the parking brake when stopping on slopes for added safety, rather than relying solely on the transmission's resistance – this also benefits clutch longevity.
As a daily city commuter, I have deep feelings about this issue. For short red lights, it's fine to stay in D gear and press the brake, but when encountering long red lights exceeding 60 seconds, I always shift to N gear. The main reason is that prolonged semi-engagement can cause temperature rise in dry dual-clutch transmissions. Once I got stuck in traffic for half an hour without shifting gears, and I could smell burning when I got out of the car. Another benefit of shifting to N gear is fuel saving - though the amount is small, it adds up over time. Additionally, many cars now come with auto-hold function which can replace brake pressing. However, I believe no function is better than shifting to N gear to completely disengage the clutch.
The key to handling a dry dual-clutch transmission at red lights lies in timing control. Here's how I do it: For short waits under 10 seconds, simply stay in D gear with the brake pressed; for stops exceeding 20 seconds, shift to N gear. When holding the brake in D gear, the clutch maintains slight friction—similar to not fully releasing the pedal in a manual transmission—which may trigger overheating protection if prolonged. Shifting to N gear allows the transmission to rest completely, significantly aiding heat dissipation. Actually, the dual-clutch's design prioritizes rapid gear shifts, so frequent switching isn't a concern. Also, always engage the handbrake when parking on slopes to prevent rollback and excessive wear.
