Protecting your car: alarm vs tracker vs immobiliser

Key Takeaways:

• Each security device serves a unique purpose.

• Modern thieves can bypass factory-fitted security.

• Aftermarket immobilisers offer superior theft prevention.

• A layered approach offers maximum protection.

With more than 61,000 vehicles stolen in England and Wales in 2024, according to DVLA data, you need to take steps to prevent your pride and joy from becoming a statistic.

While modern cars come equipped with factory-fitted immobilisers and alarms as standard, sophisticated thieves using techniques like key cloning and relay attacks are bypassing these defences.

If you’re looking to improve your vehicle’s security, should you invest in an advanced immobiliser, a GPS tracker or an upgraded car alarm?

Each device plays a distinct role in either preventing theft or aiding recovery, and understanding their strengths and limitations is key to making an informed choice.

Here, the car security experts at ghostinstallations.co.uk compare immobilisers, trackers and car alarms to help you decide which offers the best protection – or whether a combination of them all is the ultimate solution.

Car alarms offer a limited deterrent

A car alarm is often the first line of defence, designed to detect unauthorised entry or movement and alert those nearby with a loud siren.

They’re effective at deterring opportunistic thieves, as the noise can draw attention and scare off less determined criminals.

However, car alarms have notable drawbacks. False alarm triggers, which can be caused by wind, animals or faulty sensors, are common, leading to ‘alarm fatigue’.

Studies suggest fewer than 1% of people would call the police when they hear a car alarm, as many assume it’s a false alert.

Professional thieves can often disable alarms quickly, with some estimates indicating that 80% of experienced criminals can silence an alarm in under a minute.

While an alarm is a valuable deterrent and a key part of any security setup, it’s not enough on its own to stop a determined thief.

Immobilisers – stopping the engine

An immobiliser is an electronic device that prevents a vehicle’s engine from starting without the correct key or authorisation.

Since 1998, all new cars sold in the UK have been fitted with immobilisers, which has significantly reduced traditional ‘hot-wiring’ thefts.

However, modern theft methods like relay attacks and key cloning can bypass these standard systems, prompting the development of advanced aftermarket immobilisers like the Autowatch Ghost Immobiliser.

The Ghost Immobiliser requires the driver to input a PIN using the vehicle’s existing buttons, usually on the dashboard or steering wheel, before the engine will start. Drivers can also use a smartphone app to start their car with this immobiliser.

This system is undetectable, emitting no radio signals that thieves could intercept, and it effectively counters key cloning, relay attacks and hacking.

Even if a thief gains access to the vehicle or steals the keys, they cannot drive away without the PIN.

This makes immobilisers one of the most direct and effective ways to prevent theft at the point of attempt.

For those seeking top-tier protection, installing a Ghost Immobiliser is a highly recommended step.

GPS trackers – recovery and monitoring

Unlike immobilisers or alarms, GPS trackers focus on recovery rather than prevention.

A Thatcham-approved tracker uses GPS to GSM, which is the mobile phone communications network, to pinpoint a vehicle’s location in real time.

Thatcham Category S5 trackers, such as those listed on the Cat S5 trackers page, include Automatic Driver Recognition (ADR), which triggers an alert if the vehicle is moved without an authorised driver’s tag.

Some S5+ trackers even offer remote immobilisation, allowing a monitoring centre to disable the vehicle’s engine when it’s safe to do so.

Trackers are particularly valuable for high-value vehicles or those in high-crime areas, and many insurance providers offer premium discounts for vehicles fitted with a Thatcham-approved tracker, as they reduce the risk of total loss.

However, trackers don’t prevent the initial theft since thieves can still break in and drive away, especially if they bypass other security measures.

Their strength lies in post-theft recovery and as a deterrent when thieves know a tracker is present.

Which deterrent is best?

Each device addresses car theft differently, making direct comparisons complex.

Car alarms deter opportunistic thieves by drawing attention but are easily ignored or disabled by professionals.

Immobilisers, particularly advanced ones like the Ghost, are highly effective at preventing theft outright by ensuring the vehicle cannot be driven without authorisation.

GPS trackers excel in recovery, helping owners and police locate a stolen vehicle quickly, but they don’t stop the theft from occurring.

When considering the ‘best’ device, an advanced immobiliser like the Ghost stands out for its ability to stop thieves in their tracks.

Factory-fitted immobilisers are standard but vulnerable to modern techniques like relay attacks, so an aftermarket immobiliser provides a significant upgrade.

However, alarms remain a useful first layer to deter less skilled thieves, and trackers offer critical recovery support if prevention fails.

Essentially, no single device is foolproof because professional thieves can bypass alarms, and even the best immobilisers can’t guarantee recovery if a vehicle is towed or stolen via other means.

Layered security – the winning combination

For maximum protection, a layered approach combining all three devices is the gold standard.

Thatcham Category 1 systems, for instance, integrate both an alarm and an immobiliser, providing a robust foundation.

Adding a Thatcham S5 tracker enhances this setup by ensuring recovery capabilities should your vehicle be stolen.

For example, a Ghost Immobiliser will prevent a vehicle from being driven if the correct PIN hasn’t been used, and a high-quality alarm like a Toad Van Alarm deters break-ins with audible alerts.

The S5 tracker with ADR and remote immobilisation ensures that even if a thief bypasses other measures, such as through key theft, the vehicle can be located and stopped.

This combination covers all bases: deterrence (alarm), prevention (immobiliser) and recovery (tracker).

These are particularly effective against modern theft techniques like key cloning or relay attacks, which can defeat factory-fitted systems.

Your best car protection choice

Car alarms, immobilisers and GPS trackers each play a vital role in vehicle security, but none is a silver bullet.

Alarms deter but can be ignored or disabled, immobilisers prevent the vehicle from being driven, and trackers ensure recovery if the worst happens.

For the best protection, combine these systems to create a layered defence.

For high-risk or high-value vehicles, pairing a Ghost Immobiliser with a Thatcham-approved S5 tracker and a reliable alarm system is the optimal setup.

This approach not only prevents theft but also ensures peace of mind through recovery options and potential insurance savings.

Ghost Installations specialises in installing advanced security systems, including the Ghost II Immobiliser, insurance-approved trackers and upgraded alarms like the Toad Van Alarm.

Our Thatcham-approved engineers can assess your vehicle’s needs and recommend a tailored solution, whether you drive a family saloon, a luxury car or a van.

Contact our friendly team today on 0800 470 2528 to discuss the best combination for your vehicle and keep thieves at bay.