Hydrogen fuel cell cars work quite differently to conventional internal combustion engine (ICE) vehicles, in that they are essentially an electric hybrid - but with fuel cells replacing the noisy combustion engine. But how does this affect their sound? Are they quiet like EVs, or still as noisy as ICE cars?

Table of Contents

Some background

The BMW Hydrogen i8 on a race track

Combustion engines are known to be fairly noisy. They have improved in recent years due to mufflers and resonators reducing exhaust and engine noise, but the fundamental process of ICEs burning (combusting) fuel from multiple cylinders, and propeling pistons, is noisy.

So the fact that hydrogen cars don’t have an ICE should logically mean they’re produce less noise. Plus whilst gasoline-powered cars have various exhaust gases to constantly expel, the only emissions from a fuel-cell vehicle is waste water which sould also be emitted in a lower pressure (and hence lower noise) way.

The next question, then, is whether fuel cells themselves are noisy? And the short answer is: no. The hydrogen fuel isn’t burned, it’s passed through the fuel cell membrane to create the electrical power. This process itself is almost free of noise. The fuel cells do need peripheral equipment, though, such as fans and compressors. These naturally aren’t free of noise, but the overall sound given off by hydrogen fuel cell cars is quieter than conventional ICE cars.

If you were stood on the side of a road when a hydrogen car went by, the main noise you would hear would be tire noise (and maybe wind passage noise too, depending on the car’s speed). You wouldn’t hear the fuel cells (or their supporting systems) in the way that you would hear a combustion engine.

Indeed, the California Fuel Cell Partnership says:

Driving or riding in an FCV, you do notice a few differences. First, you won’t feel the vehicle change gears when accelerating or climbing hills. Second, the car or bus is very quiet. You don’t realize how loud an engine is until that sound is absent!

And whilst there’s still scarce data out there for exact dB levels for hydrogen cars, the CAFCP say that the dB levels for hydrogen compared to conventional vehicles is as follows:

Vehicle Type Average Sound (dB)
Gas Automobile 70
Diesel Bus 100
Fuel Cell Automobile 50
Fuel Cell Bus 60

Or in graph form:

So as you can see, they are distinctly quieter. It’s unclear whether this data includes things like tire and wind passage noise (especially at higher speeds when they’re louder than an engine anyway), so we’ll update this information when more dB fuel cell data is available, but it demonstrates the noise difference fairly clearly.

Videos showing hydrogen fuel cell cars

Enough talk - it’s worth seeing some clips of different hydrogen fuel-cell cars (whether they’re mainstream cars or lesser known ones) too! You can see them all in our handy playlist but we embed them below for convenience:

The now-scrapped BMW i8 Hydrogen car can be heard here from many different viewpoints, it’s a handy video. The sound produced is meant to be the natural sound of the fuel cells (and peripheral systems) instead of any fake added noise. As one of the comments says, it sounds a bit like a TIE Fighter from Star Wars!

This is the Forze VI, one of the first hydrogen race cars produced. It’s hard to hear over the background wind noise and tire-rubber-on-tarmac sounds, but this has a smoother sound compared to gasoline-powered race cars.

This British-made Riversimple Risa is shown with increased power being given to acceleration, and it sounds a bit like a sci-fi sound, or someone going through a tunnel.

This useful video is from a Honda Clarity in a dealership being turned on (but without the familiar combustion engine start-up noise we’re familiar with!), and then you can hear the faint hum of the hydrogen fuel cell systems running. It’s definitely quieter than conventional cars.

A slightly different video, showing the internal cabin noise of a Toyota Mirai car when driven at high speeds. As you’d expect, there’s definite noise at higher speeds - mostly from tire and wind noise, though, than from the hydrogen systems. Plus as the comments point out, the top speeds here (183 kmph aka 113 mph) are higher than what you can hit with most electric cars currently.

There’s a few other videos below which highlight the sound from the Toyota Mirai, Mercedes-Benz GLC F-Cell and Nissan ENV200 Fuel Cell Van at different speeds and angles:

The Nissan ENV200 Fuel Cell Van (still a concept at this stage, unfortunately) is perhaps the most interesting because diesel-fuelled vans in particular are known to be noisy, but this hydrogen van is definitely quiet.

Summary

In summary, hydrogen cars are quieter than conventional gasoline cars. They do have a definite, low-decibel sound due to their fuel cell systems, but overall tire and wind noise is likely to be higher than this anyway.

Describing sound is always tricky (hence the multiple videos above), although we’d describe the sound that hydrogen fuel cell cars make as a bit of a futuristic smooth sound.