Arguably, one of the best parts about driving a car is putting your foot on the gas and hearing that engine purr ever so sweetly. Well, that rumble may be gone forever — or at least replaced with a shallow, mechanical one.

That’s right, if you’ve bought a car within the last few years, chances are you’re not actually hearing your engine growl, but instead a recording of it.

The Washington Post broke the secret earlier this week, reporting that the noise coming from under the hood of some of your favorite cars, such as the Ford Mustang or Volkswagen Beetle, is not the actual engine but a synthetic recording of what it’s supposed to sound like.

Auto manufacturers including BMW, Volkswagen, Toyota, Porsche and Ford are all in on the deception, working hard to make sure the synthesized versions truly sound like the old car engines. Ford even polled their consumers on which sounds to implement, the Post reported:

For the 2015 Mustang EcoBoost, Ford sound engineers and developers worked on an “Active Noise Control” system that amplifies the engine’s purr through the car speakers. Afterward, the automaker surveyed members of Mustang fan clubs on which processed “sound concepts” they most enjoyed.

The article also describes how Volkswagen recreates engine noise:

Volkswagen uses what’s called a “Soundaktor,” a special speaker that looks like a hockey puck and plays sound files in cars such as the GTI and Beetle Turbo. Lexus worked with sound technicians at Yamaha to more loudly amplify the noise of its LFA supercar toward the driver seat.

This little trick is becoming the norm now, because of the more fuel efficient and advanced engines used in current automobile models. Without these little noise boxes spilling through our speakers, the car would be quiet — a little too quiet, perhaps. Automakers worry that potential buyers would view the quieter vehicles as less powerful and walk away.

Bad news for anybody who isn’t thrilled with this revelation: it looks like this illusion may be here to stay. Without the rumble, the Post writes, Federal safety officials fear the quiet, non-existent sounds of the engine could catch “inattentive pedestrians and the blind” by surprise. Mandates are expected to be finalized later this year requiring all hybrid and electric cars to fake engine sounds in order to prevent this danger.

Next time you rev the engine in your hot new ride, remember it may not be all it that it’s pretending to be.