Is Speed Limiter Removal Safe?

Speed-limiter programming can be used to set a lower operating speed for some appropriate fleet applications. Safety, reliability and legal compliance depend on the vehicle, its use and the original system. ECUFLASH assesses these requirements before recommending any programming, and does not alter a limiter required for UK-road use.

Approximately 30% of all fatal accidents can be linked to high speeds. Typically, between 40 and 60 per cent of drivers are caught doing so. Multiple studies have found that reducing just 1 km/h in average speeds can reduce fatal crashes by as much as 5%. (Source: road-safety.transport)

What is a Speed limiter?

A speed limiter is either installed by the manufacturer or by a third party on most contemporary automobiles. The vehicle's peak speed is automatically controlled and limited by the speed limiter, which is an intelligent speed assistance (ISA) technology designed for safety.

In this method, the device will stop your automobile from going any faster than you specify, which will be much gentler on your nerves when driving. So, you can drive without constantly checking your speed and worrying about receiving a ticket for exceeding the speed limit.

How do speed limiters work? 

Video or GPS-linked systems detect speed signs in Intelligent Speed Assistance systems. If the driver doesn't slow down, the speed limiter should interfere. Instead of using the brakes, it reduces engine power.

Afterwards, the vehicle's speed should decrease naturally to conform to the restricted zone.

Where programming is lawful and appropriate, ECU calibration can change limiter settings. Any change must take account of the vehicle's specification, intended use and legal requirements.

Is it safe to remove the speed limiter?

The removal of a speed limitation raises two major concerns:

• 1. Vehicle dependability
• 2. Rapid acceleration

A lower limiter setting can help a vehicle operate within a fleet's chosen speed policy, but it does not replace safe driving, maintenance or compliance with road rules.

A lower operating speed may support fuel-efficiency goals in some fleet applications, but results depend on the vehicle, load, route and driving conditions. Drivers remain responsible for complying with all speed limits.

However, removing speed limits for performance cannot guarantee safety. Most cars have a peak speed of 120 - 155 mph, which the OEM considers safe for the engine and other mechanical components - and often a number that a car will struggle to attain with its stock mechanicals. You risk a major mechanical failure when you surpass a vehicle's initial top speed by 20 - 30%.

It's also worth noting that removing speed limiters for performance on normal, daily cars is usually a waste of money unless you live near the Autobahn or a race circuit with a very long straight and your car has plenty of power and torque to reach the top speed.

What does ECU FLASH offer for Speed limiter removal?

You can disable a speed limiter in one of two ways:

• Remove the performance speed limiter (higher top speed)

Performance limiter changes are not offered for UK-road use. They may be considered only for track, off-road or export vehicles where the intended use is lawful and has been confirmed.

• Set an economy speed limiter (lower top speed)

To maximize fuel efficiency, this service is highly sought after by high-mileage private drivers and fleet managers.

Conclusion

There is no blanket answer: safety depends on the application, vehicle type, condition and legal requirements. A lower limiter setting may be appropriate for some fleets; changes intended to increase top speed require particular care and are not suitable for UK-road use.

ECUFLASH reviews each vehicle's manufacturer settings, intended use and legal requirements before discussing limiter programming. We will not disable a limiter required for UK-road use.

Let's contact ECU FLASH commercial engineers directly