How To Know If Your Car Has A Top Speed Limiter (And Can You Turn It Off?)

You've probably wondered how it would feel hitting your car's speed limit. In fact, you may have already done it on a track a couple of times. As scary as it may feel to some, there are drivers out there who want everything that their car can offer. They love the adrenaline kick of pushing the limits of their car in terms of speed. While it wouldn't make sense to try to increase the top speed of a stock Prius, Camry, or Altima, the stakes are much different if you are building a performance version of the same to get more horsepower. In that instance, it would make perfect sense to try to achieve higher speeds than factory, just to feel the potential of your power upgrade.

The top speed of a car is the maximum speed a vehicle can achieve under ideal conditions. For car enthusiasts, it's more like a key performance indicator. A top speed limiter, on the other hand, is a mechanical or digital restriction factory-set by the manufacturer to prevent a car from exceeding a set speed. 

A speed limiter shouldn't be confused with a speed governor. While both function to restrict speed, they operate in different ways. A speed governor is an outdated method of controlling speed, typically installed in commercial vehicles. The governor works by cutting fuel or restricting the spark to control speed. The speed limiter, on the other hand, is software-based and integrated into the vehicle's ECU. With a speed limiter, your car will stop accelerating past a set speed, even if you continue flooring it. The speed limit is included in the important information in the owner's manual, and you can also find it on the online spec sheet. 

Also, a speed limiter is not the same thing as Speed Limit Assist, which is designed to stop you going over the speed limit on roads, based on map data or road signs. Cars will typically display a pop-up message on the dashboard, such as "Speed Restricted." This can usually be disabled in the car's settings. In European Union countries, legislation has been put in place to ensure that all new cars include this feature.

The factory-set top speed limit is determined by several factors, including the car's aerodynamics, the speed rating of the factory-installed tires, as well as the performance of the brakes, suspension, airbags, and overall crash data. Is it possible to disable or bypass the top speed limiter? It's technically possible, but it's not recommended. However, if you are trying to bypass the manufacturer-set top speed limit, you'll need to visit a performance tuner shop and have your vehicle's ECU reflashed or reprogrammed to increase the top speed. If you decide to do it, it's important to note that it could void your warranties. It's also illegal in some states.

Before tampering with any speed settings, do some research on your specific model or engage your local car community for experienced insight. You can test the limits of your car on a closed track, away from public roads. Your car's top limit is likely well in excess of the speeds you can achieve on your daily commute, and spending some time on a racetrack could be the way to go.