Although North America lags behind when it comes to EV sales, it is undoubtedly that the flavors of the customer have started on a global basis. But what is not shifted are the vehicles themselves. With a few rare exceptions, EVs have no gearboxes with multiple speeds, and that’s because they just don’t need them. To understand why we first look at what traditional transmissions do in cars with internal combustion engines.
It all starts with how quickly those engines can run and when that RPM produces peak couple. In short – very actually – gas engines have a lower speed limits and narrower torque tires than electric motors and must use gears to make it right. The lower RPM limits are a factor of physics, because the role of the engine can only move so quickly before it causes wear and damage, and the valves of the engine cannot properly adjust the mixture of the fuel-air as soon as they exceed a certain speed. That also influences the motor torque, because if an engine runs too slowly, it cannot draw enough fuel/air to make sufficient power.
By their nature, electric motors can almost immediately deliver completely torque, and they can run up to 30,000 rpm. Let’s do a small amount of math to show how this all works.
Engineering explained explained
We are going to take our lead – and our numbers – from Engineering explained. First keep in mind that it is not that EVs have no gears, it is that their transmissions use a single gear. For example, the car from Engineering explained from Formula E, the home base of some of the best racing on the planet, and has a transfer ratio of 11.4: 1. This means that the engine has to run 11.4 times to turn the wheels once. With the engine with a red line of 20,000 rpm and taking into account the tire circumference, the result is a top speed of approximately 225 km / h (140 mph).
If a gas motor has the same transfer ratio 11.4: 1, the lower red line – for example 6000 rpm – would only be good for a speed of 67.5 km / h (42 mph). If you would like to go 140 MPH, and those who would not do that, should be the transmission ratio 3.4: 1 with the same formula. But if you would like to draw in your gas car in your gas car with 20 km / h (12 mph) in the area, the same ratio would mean that your engine would sputter with only 530 rpm – not fast enough for normal operation. So that is two different gears for two ends of the speed spectrum, and more are used for optimum driving with other speeds. The electric motor, remember, makes peak couple even while running at a low speed, and without worries about air or fuel, so that you can use the same ratio at any speed.
Exceptions to the rule
That of course does not mean that EV engines cannot be used with multi-speed transmissions. The original Tesla Roadster had a two-speed transmission when it made it debut in 2008, and today the Porsche Taycan Turbo decorations, for the sake of clarity, are EVs without turbo veins and the Audi E-tron GT, which drives on the same platform, draw up two gears.
In the Taycan, the first has a ratio of approximately 15: 1 and is intended for maximum gear. It also delivers more than, because the turbo S only takes 2.8 seconds to go from 0 to 62 mph. The second transfer ratio of approximately 8: 1 is for improved efficiency and is actually used for most driving. You have to place the Porsche in Sport or Sport Plus Modi to enjoy the first gear.
And for sensations at the next level, Track-Day fans will love the Taycan Turbo GT that upgrade to reduce its 0-60 time to 2.1 seconds (with the available Weissach Pack). The Audi variants are not that fast, with the RS E-tron seting the pace with a number of 2.4 seconds in the 0-60 sprint. Admittedly, that is a fairly expensive pair of cars, but people with more normal budgets can worry. Toyota and Ford have both patents for EV transmissions that can make it feel as if you were shifting for yourself.
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