Sedans 101: Why the humble sedan is a tremendously clever design



The three-box, four-door body shape has been the default design for automobiles because it makes plenty of sense in Singapore and here’s why

SINGAPORE

The classic idea of a car is the sedan, or saloon as it’s known in the UK.

It’s thoroughly familiar to us all, and while in today’s climate some say that sedans are boring, there are many fundamentally sound reasons why a sedan represents the best set of design and engineering choices for a great, flexible car.  

We show you why a sedan looks the way it does, what benefits it brings, and how a little clever thinking can improve on the sedan style by adding cleverly thought-out additions.

Design and the Three-box shape

Get a child to draw a car, and what they’ll doodle is a classic sedan outline, known as the ‘three box shape’.

It’s easy to see why: One box for the engine, one for the cabin, and one for the boot.

Seen like this, the pluses are clear: The boot isn’t directly connected to the cabin, which allows it to be larger, as well as transmitting less vibrations into the cabin itself.

The drawback is that a boot can’t open as wide as a car with a two-box shape (i.e. hatchback or SUV) but a car like the Skoda Octavia cleverly gets around that by having an ingenious liftback design – it looks like a sedan, but has the functionality of a hatch.


With 590-litres of stowage space, there’s plenty of room for anything a driver might need, and that expands to a huge 1,580-litres when you fold the seats down, once again the fastback hatch allows you to stow things without having to bend over or kneel down.

Another element of a sedan is the presence of four doors – again the three-box shape allows for larger, longer doors rather than shorter, vertical ones, and that allows passengers to get in or out without their feet fouling the doors.

Wheelbase

The three-box shape also allows for more space. By pushing the boot outwards and away, the distance between the front and rear wheels, the wheelbase, can be made larger. Wheelbase is often taken as a gauge of interior space – the more space you have between the wheels.

Compared to an SUV a sedan might have less headroom, but they usually make up for it in passenger comfort by having plenty of legroom.

Case in point, the Skoda Octavia has a wheelbase of 2,686mm – compared to a generic small SUV of the same price 2,600mm – which is ten cm more for your passengers to stretch their legs out. And consider the fact that in Singapore we don’t often have basketball player-tall people, but even if you do have tall friends, it’s their knees that get in the way more often than their heads.

Centre of gravity

Long and low is the unofficial sedan design mantra of a sedan. It means that not only is the car’s centre of gravity lower, but also that of the occupants.

On the move that translates to a car that handles better, and passengers that are more comfortable because they move around less.

In the Skoda Octavia, you can certainly fit five adults in comfort and safety (thanks to a spread of seven airbags) but if you could, wouldn’t you choose a car that makes effortless driving easier?

Aerodynamics

There’s a reason sports cars are all long, low and wide, and that’s to help them glide through the air with less drag.

Sedans are long as well, and while not quite as low, it illustrates yet another sedan benefit in the form of superior aerodynamics.

The Skoda Octavia has an even better aero profile, since the liftback rear reduces drag further, the better to squeeze even more mileage out of its already efficient 1.4-litre, four-cylinder TSI engine.

With a combined consumption of just 5.2L/100km. the Octavia delivers 1,000km of range on a single tankful.

Engine

Though Singaporeans’ car buying preferences trend towards ‘smallest and least expensive engine possible’, who can say no to extra power and performance for just a minimal extra cost?

The Skoda Octavia’s 1.4-litre engine may be small, but thanks to turbocharging, it packs a big punch: 150hp and 250Nm of torque to be precise, which are outputs normally reserved for large 2.0-litre engines.

Despite having more power than the competition though, the Skoda Octavia can also help lighten your load where it matters most: your wallet. Thanks to its seven-speed DSG gearbox, you could potentially go for weeks on end without needing to visit a petrol station.

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CarBuyer Team