How Speed Limiters Work

By: Patrick E. George  | 

Why Do Cars Have Speed Limiters?

Why limit how fast a car can go? Believe it or not, there are more reasons to do this than to let a car run as fast as it possibly can.

The primary reason is safety. Obviously, the roadways would be a lot more dangerous if everyone was driving well over 100 mph (160.9 km/h) all the time. The faster a car travels, the more aerodynamically unstable it is due to wind resistance, so it's hard to handle. Most drivers simply don't have the reflexes it takes to handle those kinds of speeds.


Speed limiters are also there to protect the engine and the car itself. An engine's lifespan drops significantly if it's running at maximum speed all the time because it is being made to work much harder than it normally would.

Another important factor is the car's tires. Ever look at all those numbers and letters on the sides of your tires? Those tell you not only the size of the tires but also their speed rating. The speed rating tells you the maximum velocity a tire can sustain before it's in danger of blowing out. Most family sedans and vans have S- or T-rated tires, meaning it's best to keep them under 112 mph (180.2 km/h) and 118 mph (189.9 km/h), respectively. Some exotic sports cars have Y-rated tires, which can handle up to 186 mph (299.3 km/h) [source: Tire Rack].

There are environmental factors as well. The faster a car goes, the more fuel it consumes and the more pollution it produces. In addition, law enforcement in your area probably wouldn't be too thrilled if you decided to attempt to best the Veyron's speed record.

Okay, so we've seen that speed limiters are a good thing. But what if you really want to throw caution to the wind and simply go as fast as you can? If that's the case, there are a few ways around speed limiters. Next, we'll take a look at how it's possible to disable a speed limiter.