At Autiar, engine sound is something we argue about constantly after drive days. Not horsepower. Not lap times. Sound. Because in 2025, what you hear from the driver’s seat is rarely what the engine is actually making. Modern cars don’t sound the way they do by accident, they sound that way because engineers, acousticians, and software teams decided they should.
We’ve driven enough back-to-back generations, spoken with NVH engineers, and torn through technical briefings to say this confidently: engine sound today is a designed product, not a mechanical byproduct.
The Death of “Honest” Noise: Regulations Changed Everything
Thirty years ago, engine sound was largely uncontrolled. Intake roar, exhaust resonance, valvetrain chatter, it all came through, for better or worse. That world no longer exists.
Modern constraints include:
- Drive-by noise regulations measured at fixed speeds and throttle angles
- Interior NVH targets driven by luxury market expectations
- Turbocharging, which inherently muffles exhaust pulse energy
Take a naturally aspirated BMW E46 M3 versus today’s G80 M3. The older S54 engine screamed because it physically could. The newer S58 makes more power, but the turbos eat sound energy before it ever reaches the tailpipes.
Takeaway: Engines didn’t get quieter because engineers forgot how to make noise, they got quieter because regulations and forced induction made raw sound impossible to preserve naturally.
Intake, Exhaust, and the Art of Selective Amplification
Modern engine sound is about choosing what frequencies survive.
Our team has reviewed intake and exhaust schematics where sound paths are just as intentional as airflow paths.
Common engineering tricks include:
- Helmholtz resonators tuned to amplify specific harmonics
- Dual-path exhausts with vacuum-actuated valves
- Sound symposers that pipe intake noise into the cabin
A clear example: the Ford Mustang GT (Coyote V8) versus the Camaro LT1. Both make similar power, but the Mustang’s intake resonance is tuned to emphasize mid-range growl, while the Camaro prioritizes low-frequency exhaust thump.
Neither sound is “natural.” Both are curated.
Takeaway: Modern exhaust systems don’t just reduce noise, they shape it, deciding which parts of the engine’s voice you’re allowed to hear.
Turbocharging: Power Up, Character Down
Turbochargers are the single biggest reason sound had to be engineered back into cars.
Technically speaking:
- Turbines disrupt exhaust pulse timing
- Boost pressure smooths pressure waves
- Smaller displacement engines produce fewer harmonic layers
Compare a B58 inline-six BMW to the old N52 naturally aspirated six. The B58 is stronger everywhere, but it sounds flatter. That’s not tuning failure; it’s physics.
Manufacturers respond by:
- Adding overrun crackle programming
- Injecting artificial rasp under load
- Using unequal exhaust lengths to reintroduce chaos
Takeaway: Turbo engines don’t lack sound, they lack texture. Engineering fills that gap, sometimes convincingly, sometimes not.
Check This: Why Small Turbo Engines Are Being Phased Out in Some Markets
Fake Engine Noise: Speakers, Software, and Controversy
Let’s address the elephant in the cabin: augmented engine sound.
Many modern cars, including BMW, Mercedes-AMG, and even some EVs, use synthesized audio played through speakers. We’ve tested systems where disabling it dramatically changes the driving experience.
How it works:
- ECU reads throttle position, RPM, load
- Sound profile is generated in real time
- Audio is blended with actual engine noise
BMW’s Active Sound Design (ASD) is infamous here. In isolation, it sounds convincing. Back-to-back with ASD off? The illusion cracks.
Takeaway: Artificial sound isn’t inherently bad, but when it replaces rather than enhances real feedback, drivers notice immediately.
Why Even “Good” Sound Is Still Engineered
Some cars still sound fantastic. Porsche’s GT3. Lexus’ LC 500. Mazda’s inline-six CX-90.
But here’s the truth: even those are engineered experiences.
What they get right:
- Minimal sound deadening in key paths
- Exhaust lengths tuned for harmonic overlap
- Higher redlines that create natural frequency rise
Porsche, in particular, allows more mechanical noise leakage than competitors, gear whine, valvetrain chatter, induction hiss. That’s a choice, not an oversight.
Takeaway: The best-sounding modern engines succeed because engineers allow imperfection, not because they avoid intervention.
The Psychological Side: Sound as Performance Theater
Sound influences perception more than most drivers admit.
Our team has logged identical acceleration runs with different sound profiles, and drivers consistently report:
- Faster perceived acceleration with louder intake noise
- Stronger throttle response when mid-range frequencies are boosted
- More “emotion” even when data shows no performance change
Manufacturers know this. That’s why sound is treated as a UX element, not just a byproduct.
Takeaway: Engine sound today isn’t just about emotion, it’s about shaping how fast and exciting a car feels, regardless of actual performance.
The Autiar Verdict
The Commuter
Buy. Engineered sound adds engagement without sacrificing comfort. You’ll appreciate the polish.
The Enthusiast
Wait, or choose carefully. Look for cars where sound enhancement supports real mechanics, not replaces them.
The Budget-Conscious Buyer
Skip chasing sound. Tires, gearing, and throttle tuning matter more than acoustic tricks.
Overall Takeaway: Engine sound isn’t fake, it’s intentional. The problem isn’t engineering itself. It’s whether the engineering respects the machine underneath.
High-Intent FAQ
Is fake engine sound becoming unavoidable?
Not unavoidable, but increasingly common as regulations tighten.
Can sound engineering improve reliability?
Indirectly. Quieter engines experience less perceived stress, but mechanical reliability is unaffected.
Will EVs make this debate irrelevant?
No. EVs already use engineered sound, for safety, branding, and emotion.
At Autiar, we don’t believe engineered sound is a lie. We believe it’s a language. When spoken fluently, it enhances the drive. When spoken poorly, it reminds you something real is missing.
