Here's a strange thing about electric cars: they're quieter than petrol cars — and yet, in some situations, they can sound noisier. Owners report wind noise on the motorway that seems louder than it ever was in their old car. Passengers notice rattles and hums they never heard before. The overall sound level is clearly lower, but something feels... off.
It's not your imagination, and it's not a flaw. It's one of the most counter-intuitive facts in modern car engineering — the NVH paradox. And once you understand it, you'll never listen to a car the same way again.
1. The engine was hiding everything
For a century, the internal combustion engine defined the sound of driving. The hum of the engine, the whirr of the drivetrain, the rumble of mechanical friction — together they formed a constant acoustic background. It was loud enough to mask other sounds, but steady enough that your brain tuned it out. It was the sound of "the car is working".
An electric car removes that background. The motor is nearly silent. And when a constant masking sound disappears, everything that was hiding behind it steps forward.
This is the first half of the paradox: the car isn't noisier — it's clearer. The background that used to cover things up is gone.
2. What the silence reveals
Once the engine's masking is gone, three sound sources become prominent — in nearly every electric car model:
Wind noise. At speed, air rushing over the bodywork, mirrors and window seals becomes the dominant sound — especially above 90–100 km/h.
Road noise. Tyres on the surface transmit vibration and hum into the cabin, particularly on coarse asphalt.
High-frequency whine. Electric motors and their drive systems produce a lighter, higher-pitched sound than an engine — and it's more noticeable precisely because it's new to the ear.
Here's the second half of the paradox: the overall sound level in an EV is genuinely lower than a petrol car's. But a low, steady rumble is easy to ignore, while an intermittent whistle or whine is hard to ignore. It's not about volume — it's about noticeability. A car can be quieter in decibels and louder in perception.
3. Why wind noise matters most at speed
Of the three, wind noise is the one that surprises owners most — because it grows quickly. Aerodynamic noise rises dramatically with speed — far more steeply than most people expect. The difference between 90 and 110 km/h is bigger than it sounds.
On the motorway, air rushing around the A-pillars, wing mirrors and window seals can dominate the cabin. And because there's no engine note to cover it, what was once a background whisper becomes the foreground sound of the journey.
This is why two cars with identical decibel readings can feel completely different on a highway trip — the quality, frequency and consistency of the sound matter as much as the volume.
4. How engineers control it
Controlling noise in an EV is a design discipline in its own right — NVH (noise, vibration and harshness), and one of the most demanding areas of electric car technology. Engineers work across several fronts:
Acoustic treatments. Layers of sound-absorbing and insulating materials in the floor, doors, roof and dashboard — the "acoustic package" that determines how much noise reaches your ears.
Glass and seals. Specially laminated glass and carefully designed seals reduce wind and road noise transmission.
Tyres and wheels. Tyre design and wheel-well treatments manage the road noise that coarse surfaces generate.
Digital prediction. Modern engineers don't wait for a prototype to find noise problems. Using simulation — computational fluid dynamics for the airflow, and statistical energy analysis for how sound travels through the structure — they can predict wind noise before a single physical car is built. Acoustic treatments can then be tested virtually.
That last point matters more than it sounds. It means the "sound of the car" is now designed and tuned like any other performance characteristic — not discovered by accident at the end of development.
5. What this means when you're buying
Because perception matters more than decibels, the way you test an EV's quietness should change:
Drive at motorway speed, not just around town. Wind noise only appears at speed — a 10-minute highway loop tells you more than an hour in the suburbs.
Listen for what you hear, not just how much. A constant hum is more comfortable than an intermittent whistle, even at the same level.
Check the second row. Rear passengers hear road and wind noise differently — and that's where your family will be sitting.
Try coarse roads. Rough asphalt reveals how well the tyre and acoustic package work together.
A "quiet" car that sounds smooth at every speed is the result of deliberate engineering — not luck, and a point worth testing when comparing electric cars in Australia.
6. XPENG: treating sound as an engineering discipline
This is where XPENG's approach comes into focus. Quietness in the NEW G6 electric SUV and the X9 isn't an accident of electric drive — it's an engineered result.
The body and acoustic package are designed to manage wind and road noise at speed, where the paradox bites hardest. The AI-driven chassis plays its part too — adjusting the dual-chamber air suspension continuously to keep the body stable and reducing the vibration that would otherwise reach the cabin as noise. Sound, structure and suspension are tuned as one system.
The goal isn't simply "a quiet car". It's a car that sounds calm — no sudden whistles, no intrusive whines, no background that makes you turn up the conversation. In an EV, that's the real luxury.
Conclusion
The quietest car isn't necessarily the most comfortable — because the sounds we notice aren't always the loudest. An EV reveals what an engine used to hide: wind, tyres, and high-frequency whine. That's why a quieter car can sound noisier.
But the paradox has a solution, and it's engineering. Acoustic packages, glass, tyres and digital prediction have turned cabin sound from an accident into a design choice. The best EVs don't just measure low on a decibel meter — they sound calm where it counts, at speed, on real roads, for everyone inside.
Ready to hear the difference big NVH engineering makes? Book a test drive with XPENG — one of Australia's leading Chinese EV brands — and take the NEW G6 or X9 on a motorway loop. Listen to yourself.
Note: Driving characteristics and feature availability vary by model and specification. Subjective perception of noise varies between individuals.
