Do electric cars have gearboxes?

Cars with conventional internal combustion engines need gearboxes to get engine power to their wheels. Generally, electric cars don’t. We find out why.

Electric cars do more with less, and this is particularly true of the way they get motive power to their wheels. Generally electric car motors are connected directly to their road wheels, often with single, fixed gears but without a manual gearbox or automatic transmission with all their cogs and other efficiency-sapping mechanical bits coming between the two.

The Taycan might look complicated, but its nothing compared to a conventional petrol Porsche

Running out of puff

If you’ve ridden a bicycle uphill you’ll know how difficult things become if you don’t shift into a lower gear. On the flat you can go faster by using a higher one. Conventional petrol and diesel cars need gears for the same reason. The amount of power their engines produce is limited and will be delivered at a peak engine speed (measured as ‘revs per minute’ or RPM). Higher gears allow this power to be used at higher speeds. Although many fossil fuel engined cars have stop/start systems to reduce emissions, they need clutches to allow gears to be changed and to prevent their engines stalling when the cars stop. Electric motors don’t stall, they just stop when a car comes to a halt.

Instant power

They also produce maximum pulling power, or torque, as soon as they begin turning, and their power doesn’t decline the faster they go. A petrol motor might run out of puff at 4,000rpm, but an electric one is still delivering at 20,000rpm, a speed very few internal combustion motors can match. Not having a transmission with forward and reverse gear means that, amusingly, an electric car’s motor would be capable of going backwards as quickly as it can to forwards. This dodgy state of affairs is prevented from happening by software.

Electric cars could go as fast backwards as they can forwards if the electronic limiter didn't spoil the fun

Exceptions

So that settles the ‘gear or no gears’ argument then. Well, not quite. Many plug in hybrid petrol/electrics have old school self-shifting transmissions, and the all-electric Porsche Taycan and Audi RS e-tron GT have two speed geraboxes. The twin-motored Taycan’s transmission lives in its back axle and allows motive power to be disconnected from the rear wheels, so the Porsche becomes front driven. Its twin speed box’s lower ratio is also claimed to improve acceleration. The higher ratio, which effectively lowers motor to road wheel speeds is engaged the rest of the time and allows a higher top speed (essential for a car sold in Germany where the Autobahns have no speed limit) and better range. RS versions of the Audi e-tron GT use similar systems for similar reasons.

The Croatian-made Rimac Nevera hyper car actually has three gearboxes, with a couple of two speeders working with each rear wheel, and a single speed box to help get power to the pair at the front. This car is theoretically capable of 258mph and 0-60 in 1.85 seconds.

You can expect to see this sort of technology in some other future electric performance cars.

L plates

At the other extreme there’s a Chinese electric car with a fake five-speed gearbox, so people can learn to drive using it and get a licence for a manual car. This is the nattily named Chery New Energy eQ2 Driving School Version, and if nothing else it will cut the emissions generated by learner drivers as they receive instructions by the roadside, engage in slow, wheel-shuffling three point turns or reverse in a wide arc round corners. It is unclear whether the Chery New Energy eQ2 Driving School Version bunny hops in a conventional car style if its ‘clutch’ is abused by inexperienced feet.

Retrofitted

Finally, we come to some electric cars that have conventional gearboxes because they were originally designed for conventional engines. These are classic cars that have been given heart transplants, switching petrol to electric motivation. Bolting an electric motor onto an existing gearbox is simpler and cheaper than ripping it out and perhaps having to modify other drive components to make the car go. Everything from old Land-Rovers to dinky Fiat 500s have received this treatment.

A good example of this trend is a new old design, in the form of the Russian-made MWM Spartan electric 4x4. This upright, square car can trace its rootsback to 1971 and has retained its gearbox and four wheel drive bits. With an electric motor the driver puts it into top gear and doesn’t bother with the gear lever after that - although if they plonked it into first and engaged low ratio it would probably have mountain bike gearing, and gravity permitting, haul itself to a near vertical stance. A word to the wise: We don’t recommend this.