Question

What is ASL in cars?

Depending on the make and type, ASL in cars may serve different tasks. ASL in cars can either mean Automatic Speed Limiter or Automatic Sound Leveling.

Automatic Speed Limiter

If your car has an ASL – Speed Limiter feature, you’ll be able to find the ASL button on the steering wheel or close to the gear shifter. The ASL button in cars activates an Automatic Speed Limiter. This function, found on some Jaguars and other vehicles, caps how fast you can go. The car will accelerate up to the maximum speed the driver has set. After that, the vehicle’s top speed is limited until the ASL feature is disabled. 

Automatic Sound Leveling

In the context of sound, “ASL” stands for “Automatic Sound Leveling.” This function will automatically adjust your stereo’s volume based on a few factors you set. For example, this can make the audio coming out of the stereo louder if traveling at high speeds. The ASL in cars is not a common feature, but it can be found on some top-end models.  

A microphone inside the car detects ambient noise levels and automatically adjusts the car’s audio system’s output (mostly the volume) to match. Noise from the road, the tires, the wind, and other sources tends to rise when a car approaches highway speeds. As your speed increases, the sound system responds by increasing the loudness of your sound system, and vice versa as you slow down.

If the ASL Button sits in a common area, such as by the wheel or the cruise control, it is likely to function as a speed limiter. The proximity to the audio controls suggests it is for sound leveling purposes.