What does double locking your car do?
Double locking engages a deadlock mechanism that prevents the doors from being opened from inside, and it usually requires a key or remote to open from the outside. The exact behavior varies by make and model.
What double locking does
Double locking, also known as deadlocking in many vehicles, is designed to deter theft by isolating the door latch from the interior release. It typically activates after the doors are closed and locked, and its effects can differ depending on the car.
Core effects
Before you review the key outcomes, it helps to know what to expect when deadlocks are engaged.
- Interior door handles are disabled from opening the door when the deadlock is engaged.
- Exterior entry typically requires the proper key or remote to unlock; the external door handle won't release the latch while deadlocked.
- Some models also disable interior trunk releases or other interior access points when deadlocked.
- Deadlocking is different from ordinary locking and is commonly labeled as a “deadlock” or “double lock” in vehicle manuals.
In practice, double locking adds a layer of protection against forced entry, but you still need the correct method to re-enter the vehicle.
How to engage double locking on typical cars
The practical methods to activate deadlocks vary by vehicle, but there are several common approaches you’ll encounter.
Common engagement methods
Before listing the typical methods, note that exact steps depend on the model and year.
- Key fob: Press the lock button twice in quick succession to arm deadlocks on many modern cars.
- Driver’s door: Use the physical lock switch or the key in the driver’s door; some models require turning the key to the lock position again or holding it briefly to activate deadlock.
- Inside switch: Some cars allow deadlocking via the central lock button and then closing the door, or via a dedicated deadlock switch in the cabin.
Because methods vary widely, consult your owner’s manual or test the function safely at a stop to confirm exactly how your vehicle’s deadlocks operate.
Practical considerations and limitations
Double locking is a security feature, but it is not a guarantee against theft or unlawful entry. It is one part of a broader approach to vehicle security.
Key considerations
- Not a substitute for parking in well-lit, safe areas or for taking steps to conceal valuables; always carry your keys and keep windows up.
- In an emergency, interior egress may be impeded; ensure you can exit quickly if needed.
- The exact behavior of deadlocks—how they engage, how to unlock, and what components get locked—varies by model and year; consult the manual for precise instructions.
In daily use, double locking adds a protective layer against opportunistic theft and door prying while leaving the standard unlocking method as the way to re-enter.
Summary
Double locking activates a deadlock that prevents the interior door handles from opening the door, and in many cases requires the key or remote to re-enter. The feature’s specifics vary by car, so check your manual to understand exactly how yours works. Use it when parked in riskier areas as part of broader security practices.
How does a double lock work?
Double locks are all about doubling up on security with two locking mechanisms on one door. Usually, this means a deadbolt lock paired with a standard knob lock, with the deadbolt sitting above the knob lock. Hence, this dynamic duo makes it much harder for anyone to break in, giving you a feeling of safety.
Are double locks easy to break in to?
Deterrent to Break-ins
While no lock can provide 100% security, double-cylinder deadbolts can serve as an effective deterrent to would-be intruders. The added complexity of needing a key on both sides makes these locks less attractive to burglars who are looking for an easy target.
What is the point of double locking your door?
Doors have two locks primarily for enhanced security, providing a more difficult obstacle for intruders to overcome. This dual-lock system typically consists of a deadbolt and a standard doorknob lock, which works together to increase resistance against forced entry. Two locks, positioned apart, also help to distribute the force of an attack, making it harder to break the frame or the lock itself.
This video explains how multi-point lock systems work and their benefits: 58sThe Window ExpertsYouTube · Aug 13, 2023
Key reasons for using two locks
- Increased security: A second lock, such as a deadbolt, provides a stronger barrier. The deadbolt has a longer throw and a stronger bolt, making it harder to "jimmy" open compared to a standard spring latch on a doorknob lock.
- Resistance to force: Two locks on a door spread the load, meaning the force from a kick or a battering ram is shared between two points. This makes it more likely for the door to hold up against brute force attacks.
- Resistance to picking: While lock picking is not common for most break-ins, having two separate locks means a potential intruder must defeat both to gain entry.
- Added convenience: A combination of a deadbolt for security and a knob lock for convenience allows for quick, keyless entry and exit when the deadbolt is not engaged.
- Peace of mind: For some, especially those with doors that have glass panels, a second lock offers a greater sense of security and safety.
- Prevention of unsupervised exit: In homes with children or individuals with cognitive impairments, a double-cylinder deadbolt (requiring a key from both the inside and outside) can prevent unsupervised exits.
What does locking your car twice do?
Double locking ensures that opening the vehicle from the inside (for example, after glass breakage) is no longer possible.
