While most British drivers own a car with a manual gearbox and a third pedal called the clutch, you may have heard about automatic cars which have no clutch pedal.
But what exactly is the difference and why would you choose to use one or the other? Keep reading to find out.
What’s the difference between a manual and automatic transmission or gearbox?
In extremely simple terms, a manual transmission requires you to change your car’s gears manually, hence the name. That means shifting the gear stick from one gear to the next while simultaneously operating a clutch pedal. This added involvement means manual gearboxes might appeal to you more if you enjoy driving.
A manual gearbox has many other advantages, though. It’s mechanically simple, which means manual cars are cheaper to buy than cars with an automatic gearbox. Compared with a traditional automatic, they’ll also be better on fuel and quicker.
In a traditional automatic car, well, it does all the gear changing automatically. You simply slot the gear stick into D (for Drive) and let the car do the rest. You can even hold the car on the brakes without needing to worry about the clutch pedal which is just as well because, in an automatic car, there is no clutch pedal.
What kind of driving licence do you need to drive an automatic car?
Most British people have a manual driving license, which actually means they can drive both a manual and an automatic car.
Why is this? Well, a manual car adds an element to driving that you don’t have to worry about when driving an automatic – as well as accelerating, steering and braking, you have to operate the clutch and shift the gear stick as you drive. So, if you’ve passed your driving test in a manual, you’ll find an automatic car even easier to drive.
Get an automatic driving licence and you’ll be restricted to driving automatic cars. That said, driving an automatic car is easier, so if you want to pass your driving test as quickly as possible, an automatic car will stack the odds in your favour.
What are semi-automatic cars?
A small number of cars are available with a semi-automatic gearbox, essentially this is a manual gearbox with an electronically controlled clutch. Semi-automatic cars don’t have a clutch pedal but some do require you to select your gears. They tend to be fitted to small cars – including the VW Up and Citroen C1 – because they’re easier to package than a bulky fully automatic gearbox.
That said, semi-automatic gearboxes don’t tend to be as smooth as a conventional automatic or a well-driven manual – they can be particularly jerky when you’re carrying out low-speed manoeuvres like parking. On top of that, they can also be very slow to change making the car feel not as quick and also less efficient.
If you still want a semi-automatic car then the VW Up is worth a look. It’s a very easy car to drive in town and fitting the semi-automatic gearbox means you don’t have to knacker your left leg operating a clutch pedal.
What’s a continuously variable transmission (CVT)?
Instead of using conventional gears, a continuously variable transmission has a belt drive mounted on two cone-shaped pulleys – the gap between these pulleys opens and closes to give you higher and lower gears. Because the CVT gearbox has an infinite number of gears, there’s no need for your car’s engine to work through its rev range, instead, it can always operate at its most efficient engine speed. For this reason, CVTs are an ideal match for fuel-efficient hybrid cars such as the Toyota Prius.
While a CVT’s gearbox lets a car’s engine work at its most efficient and saves fuel, it’s not all good news – under hard acceleration CVT-equipped cars emit a steady drone that can become tiresome. While CVTs help a car be more efficient, they’ll also make a car slower because they don’t let a car make full use of its rev range.
As noted before, if you’re looking for a great example of a car fitted with a CVT gearbox, consider the Toyota Prius hybrid. Its CVT gearbox helps it return spectacular fuel economy and also makes it an easy car to drive.
What is a twin-clutch automatic gearbox?
A twin-clutch gearbox, unsurprisingly, has two clutches and odd and even gear sets. There’s no clutch pedal instead you usually change gears either using the gear stick or the paddles behind the steering wheel.
The odd and even gear sets mean when the gearbox is in, say, third it can preselect fourth, spinning fourth gear up to speed so that when you actually change up from third to fourth the change is smooth and quick. A twin-clutch gear change takes about 8 milliseconds versus a full second for a manual car.
The small gap between gear changes also makes twin-clutch automatics more efficient than a traditional auto because the car’s wheels are almost always connected to the engine, little power is wasted. As a result, twin-clutch gearboxes are also popular on mainstream cars such as the Volkswagen Golf and Ford Focus.
Twin clutch gearboxes do have their problems, though. They can be a little jerky when you’re making off and their complexity means they weigh more than a standard manual gearbox – which means they’re not usually quite as cheap to run as a manual car. Their complexity also means twin-clutch gearboxes cost more to buy than a manual gearbox and they can also be less reliable, though, this is more relevant to older cars with early dual-clutch gearboxes.
The Volkswagen Polo is one of the cheapest and best ways to get your hands on a car with a twin-clutch gearbox. Not only does its seven-speed DSG make it easy to drive in town, but its extra gear (the manual car only has six speeds) also makes it a quiet motorway cruiser.
What’s a traditional automatic gearbox?
The traditional automatic gearbox is also known as the torque converter automatic. In a traditional automatic gearbox the torque convertor does the job of the clutch, forming a viscous oil connection between the engine and the wheels.
This allows for extremely smooth, in some cases almost imperceptible gear changes – which is why this type of gearbox is fitted to luxury cars such as the Mercedes S-Class.
Unfortunately, the lack of a physical connection between the engine and the wheels means a traditional automatic isn’t very efficient, so your car will cost more to run. An automatic gearbox also costs more to buy than a manual, which will add to the overall price of a new car.
The Mercedes S-Class comes as standard with an automatic gearbox that offers smooth shifts that are an excellent match for the car’s quiet and comfortable interior.