A smooth and comfortable driving car makes for a pleasant commute and happier passengers
When you get into a car and close the door, how much of the outside world do you shut away? A passenger car comes with its own set of sounds on the go. Car designers make a lot of effort to minimise it, but on the move, there’s a combination of wind noise, engine vibrations, tyres rumbling on the road, and the small movements of hundreds of parts in the car’s suspension system that add up.
The combined result is a symphony of noise that car designers actually have a rating scale for, the NVH (noise, vibration, harshness) level. It is the measurement of aural and tactile feedback in an object, and in this case, a car on the move. That’s a lot more than just saying that a car is ‘noisy’ on the move!
Using certain materials in the construction of a car and specialised build methods help to keep noise and vibration down, and some carmakers do place more importance on this aspect of designing a car than others. Let’s see how this all comes together.
How noisy can a car get?
While you would not associate sports cars like a Toyota GR Supra to be very quiet, as the tuned sounds and feel of its 3.0-litre engine is integral to the driving experience, an executive sedan like the Toyota Camry Hybrid, with its priority on a comfortable drive, will offer a much calmer cruising experience.
Image: Toyota Camry Hybrid
People have differing levels of noise tolerance, and it’s typically a subjective experience; if you owned a comparatively noisy compact car for years and step into something just that bit quieter, it can feel like a major improvement, but if you’ve been riding in a large, quiet luxury car then hop over into a small car the increase in noise levels can be quite jarring and unsettling.
As we briefly summarised earlier, the sounds you get in a moving car come from a variety of sources. Wind noise is actually a big part of this. Car designers build aerodynamically shaped cars not just for better efficiency, but they are also shaped to reduce the flow of turbulent, noisy air over the car. A car that’s well-shaped can greatly reduce the issue of wind noise at high speed.
Then there’s road noise, which is a combination of rolling tyres, and the surface that it’s rolling on. Smoother tarmac surfaces tend to be quieter, but this is also interacting with the main contact points on your car, the rubber tyres. Paradoxically, both budget tyres and high performance sports tyres tend to be rumbling, noisy affairs that send the sound of them rolling on the road through a car’s cabin. Yet there are tyres designed for minimal rolling noise, though sometimes at the expense of the tyre’s lifespan.
A car is made up of thousands of components and when on the move things can rattle about, adding to the cacophony of sounds you hear. Modern cars have suspension components riding on rubber bushings to cushion and dampen out a lot of vibration that would be transmitted through the suspension arms, and then there’s the matter of the actual powerplant.
Petrol and diesel engines both produce power by igniting fuel and having the explosive energy be converted to rotational forces. As you can expect, that creates a lot of noise and vibration. A paradox here is that large capacity engines are usually quieter than small engines in urban traffic, as they do not have to work as hard as a smaller engine to get a car underway.
However the gradual acceptance of electric vehicles into mainstream use may eventually see the end of the internal combustion engine as a source of noise and vibration, but there’s also an in-between with petrol-electric hybrid technology that can present you with the best of both worlds. Cars like the Toyota Yaris Cross Hybrid and Sienta Hybrid pack a fuel efficient internal combustion engine together with an electric motor under the hood, and with the big leap in battery technology over the last couple of years, are capable of cruising for decent distances with only the electric motor powering the car.
A quiet car means a more relaxing drive, anywhere
But wait, isn’t a quiet cabin the exclusive domain of very expensive luxury cars?
Actually it isn’t, and it’s time to debunk that myth right now.
The gradual electrification of automotive powertrains over the last two decades, leading to the mainstream proliferation of petrol-electric hybrids and electric vehicles, have had the added bonus of giving us cars that are quieter than ever, all within the reach of many car owners. But there’s also a lot more to the technology of making cars quieter and more relaxing places to be in.
Toyota places great priority on building cars with favourable NVH ratings, and the Japanese carmaker is also one of a handful that uses double glazed windows to cut down on external noises coming into the cabin. Additional premium insulating materials reduce the ingress of external noises even further. The brand’s new TNGA (Toyota New Global Architecture) modular chassis, built to be infinitely configurable for various cars and powertrains, is actually also designed to reduce acoustic resonance within the frame itself so that the components of the car don't generate any undue noise on the move.
This attention to detail from Toyota also extends to the use of comfort and fuel efficient based tyres on its family cars. The rubber and silicone in these minimise rolling resistance, allowing the car to roll further with less power and fuel consumption.
Toyota offers affordable, value for money hybrid cars that are quiet, comfortable, and efficient
From a compact runabout to a big car for a large family, every Toyota has been built to the leading specifications of what constitutes a quiet, comfortable car. Even the seven-seater Toyota Sienta Hybrid, a small but efficient MPV with a highly efficient petrol-electric drivetrain, is one of the quietest and smoothest cars in its class.
Image: Toyota Sienta Hybrid
If you want a large, classy, and luxurious urban SUV, the Toyota Harrier Hybrid offers up luxury levels of class with a cabin that’s as comfortable as a five-star hotel.
Image: Toyota Harrier Hybrid
How about a vehicle for moving more than five people in total luxury? Toyota’s posh, luxury MPVs in the form of the Alphard and Vellfire Hybrids are worldwide class leaders in efficiency and comfort. Step into one, and you’ll need no further convincing on how awesome they are to take a ride in.
Image: Toyota Alphard Hybrid
Image: Toyota Vellfire Hybrid
In petrol-electric hybrids like those from Toyota, intelligent power control systems manage the energy flow between the petrol engine and electric powertrain. It changes between them as necessary so quietly that the car’s occupants will typically never notice the changeover. You’ll notice the benefits though, in the form of a more comfortable car that exhibits less vibration and noise than the competition.
The extended driving range of a petrol-electric hybrid also means that you need to visit service stations a lot less too. Just think of the time saved from queuing to refill your car, over the course of a year!
Petrol-electric hybrids have always had highly reliable batteries as the power source of the electric engines since the first generation Toyota Prius, the iconic car that showed the auto industry how hybrids can be both comfortable, reliable, and fun. In fact, a Toyota Prius Hybrid taxi in Vienna, Austria was officially recorded as having covered 1,000,000km and remained in perfectly serviceable condition.
Petrol-electric hybrids also record lower maintenance costs. Their engines are less stressed in daily use, resulting in lower incidences of engine trouble. Furthermore, their batteries are very reliable, and regenerative braking systems help reduce the need to step on the brakes, improving the longevity of the car’s mechanical components
A quieter car is not the exclusive domain of luxury cars. Especially in a busy, urban space like Singapore, the ability to shut out noise while on the go is advantageous to help you clear your mind on commutes, between business meetings, and allow babies to nap soundly in their car seats!
Toyota has you covered with a comfortably quiet hybrid for every need and budget, from the fun and funky Toyota Yaris Cross, the adventurous Toyota Corolla Cross, to the executive sophistication of the Toyota Camry Hybrid and the luxurious Toyota Alphard and Vellfire Hybrid MPVs. As the powerhouse of the Japanese automotive industry, Toyota knows how to build cars that suit the budgets and needs of everyone.
But don’t feel overwhelmed just yet, as you can browse through Toyota’s comprehensive lineup in full online at www.toyota.com.sg. Be assured that from the quietest of magic carpet rides to the sportiest engine notes, the brand has a car that delivers to you exactly what you want.