Do electric cars have engines? And gears? Here are the answers | The Citizen




While more and more electric cars are being offered in South Africa, they’re still a fairly uncommon sight on local roads.

As a result, the buying public’s natural lack of familiarity with battery-powered vehicles means many people have broad questions on a topic that requires specific answers.

One question on many people lips is: do electric vehicles (EVs) have engines?

The answer depends largely on the meanings assigned to the words used. For instance, the Collins dictionary defines an engine as “any machine designed to convert energy into mechanical work”. Using this rationale, an electric car would indeed have an engine.

However, the Cambridge dictionary defines an engine as “a machine that uses the energy from liquid fuel or steam to produce movement”. Here, the specific requirement that an engine makes use of “liquid fuel or steam” would mean an EV doesn’t have an engine, since it is powered by electrical energy. Of course, it doesn’t help that the meanings of words tend to change over time (and some even differ according to region).

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In South Africa’s automotive industry, however, the latter definition is the more widely accepted one. Since EVs employ an electric motor that draws energy from a rechargeable battery pack rather than a conventional internal combustion engine, battery-powered cars don’t have an engine in the traditional sense.

The CItizen Motoring took a closer look at how electric cars work to find answers for the more questions on the topic.

The Jaguar I=Pace was one of the first fully electric cars offered in South Africa.

Do electric cars have gears?

Typically, electric cars use single-speed transmissions. This means they have just one gear and thus no clutch. Technically, therefore, EVs don’t have a gearbox in the traditional sense of the word which is loosely defined as a “set of gears within a casing” as there’s only a single ratio.

Most internal combustion engine-powered vehicles utilise multi-speed gearboxes since such powerplants generate their usable power and torque across a relatively narrow band. And flitting between a variety of available ratios allows the engine to stay mostly within this band.

That’s not the case when it comes to EVs. For example, the electric powertrain in the Volvo XC40 P8 Recharge makes its peak torque of 660 Nm virtually instantly. And sustains it over a far broader band. As a result, it doesn’t require more than one gear.

Watch all-electric Volvo XC40 in action

That said, there are a couple of EVs on the market that use two-speed transmissions, but these are firmly in the minority. In addition, some all-wheel-drive Tesla models use a different gear ratio in their front and rear drive units.

Do electric cars use oil?

Since an all-electric car doesn’t have a combustion engine with a multitude of moving parts to lubricate – such as valves and pistons – it doesn’t require engine oil. Hybrids cars, however, do need oil as they have both traditional engines and electric motors.

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That means EV owners don’t have to worry about oil changes. However, it’s worth pointing out most battery-powered cars do use some form of oil to lubricate components such as the single-speed transmission, though these oils normally don’t require routine changing.

Electric cars Volvo XC40
Instead of an internal combustion engine, the Volvo XC60 P6 features a plastic cover with storage space over its electric motor.

Do electric cars have brakes?

It may sound like a silly question, but again the answer is a multifaceted one. The average EV actually boasts two primary methods of deceleration. Traditional hydraulic brakes like the type you’re likely familiar with from petrol and diesel-powered cars, and regenerative braking.

The latter essentially forms part of an energy recovery system that redirects some of what would otherwise be wasted kinetic energy back into the battery. In short, when the driver lifts off the accelerator, the electric motor reverses its direction of rotation, both slowing the vehicle and effectively acting as a generator to charge up the battery.

Some EVs, such as the Volvo XC40 P8 Recharge, have a one-pedal driving mode. This renders the regenerative braking effect strong enough to allow the driver to bring the vehicle to a complete stop without employing the friction brakes at all. It may sound a bit bizarre, but it’s actually a really intuitive way of driving.

This also greatly reduces the vehicle’s reliance on its hydraulic brakes, which ultimately results in less wear and longer lasting braking components.

Even more importantly, it increases the electric car’s range by topping up the charge in the battery pack.





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