why electric cars don't have transmissions

Do Electric Cars Have Transmissions?

by

Noel Joseph
August 17, 2021
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Electric cars—and we’re talking full EV, not hybrids—are the way of the future.

Billions are being poured into charging stations for electric cars all across the United States right now, and companies like Tesla will continue to build hundreds, if not thousands of Superchargers as often as they can.

But can electric cars really match the long distance capabilities and power of combustion engines?

Is that something we can rely on? We can, and it’s because of one aspect of combustion engines that didn’t make it into the final design for electric cars.

Do electric cars have transmissions? Nope. and this is why.

Why Don’t Electric Cars Have Transmissions?

transmission in electric cars

Let’s first look at the major difference between EV cars and combustion engine cars.

With a combustion engine, there are gears in place, and these gears help shift the mechanics inside of your engine to hit specific speeds.

1st gear has a different speed range than 2nd gear, and so on. Once enough power from the combustion engine hits the next gear, the transmission shifts gears (automatic versus manual transmissions).

With an electric vehicle, transmissions don’t exist because this function isn’t needed. We’re not relying on combustion energy to help push the engine forward, or into the next gear. In fact, there aren’t really gears, per se—it’s just a direct feed from the battery to the engine to make it move.

This is far more energy efficient. If you hit the minimum speed threshold in a traditional combustion engine gear, you’re supplying enough power to run that gear even if you barely require the power that gear offers.

Instead of having four gears that alternate between different speed ranges, it’s like having a gear for every different level of speed, because your EV is only going to output the necessary amount of energy to make your car run the way you want it to.

Advantages of Having Car Without Transmission

transmission gears

There’s more than one reason that it’s great to forgo requiring a transmission altogether. These are a few of the best reasons.

  • Less Expensive to Maintain: If your transmission is slipping in a combustion engine vehicle (most of us have been there), then you’re basically up the creek without a paddle. You’re on a ticking time clock, and repairs can range from $1,600 up to $4,500 depending on the vehicle you drive. That fear is literally gone—poof; it doesn’t exist.
  • Quiet Operation: Transmissions tend to be what causes that loud rumble and roar in combustion engine vehicles. Without having one, your car operates at whisper-quiet operation in comparison. This is beneficial if you don’t like the loud rumble of your car when it’s heating up in the morning, or if you’re headed out in the middle of the night and don’t want to wake up the neighbors. Plus, it’s just a nicer feeling while actually driving the car.
  • Easier Diagnostics: Not sure what’s wrong with your EV car? The good news is that you don’t have a dozen-or-so issues that can be tied back to the transmission, which is fairly common in combustion engine vehicles. Diagnosing issues in the engine of your eclectic car is easier without a transmission, and for plenty of other reasons.

Not having a transmission helps with other aspects as well, although inadvertently. For instance, electric cars have regenerative braking, which means that they use all the wasted kinetic energy from stopping the vehicle, and turn it into electricity to be stored in the battery.

Part of what makes that possible is not forcing hydraulic fluid and brake discs to collide to stop all that power from a combustion engine. It’s a lot more labor-intensive for your vehicle to slow down after lowering gears from combustion energy versus an electric source.

Are There Electric Cars With Transmission?

manual transmission roadster

Yes, there are electric cars with transmissions, but they’re not in production anymore. The original Tesla Roadster was one such vehicle, where you could manually switch between gears.

In the infancy of electric motors, they began with a formula that worked—combustion engines, with transmission and gears and everything in between, and slowly weeded out what was  no longer necessary for that design.

The thing is, this is an appealing concept to some people—an electric car with a drivetrain transmission that can be manually adjusted. Whether it’s a four-speed or a simple two-gear transmission, some folks want to have that level of control and feeling that they’re interacting with their car.

Thankfully, there are specialty shops that can turn this dream into a reality. Plenty of classic car enthusiasts want to be able to use their favorite designs or treasured vehicles, but make the switch to being a full EV vehicle. These shops basically perform car surgery and remove the combustion engine and its vital components, and turn your classic car into a full EV.

That’s where the transmission question comes back into play—since the area is already cut out for a manual transmission, and older electric cars were known for having stick shifts, you can opt for that and still have the same feel. It’s a classic electric car; turns out you can have your cake and eat it too!

We want to put a note here and say that transforming an older, classic car into an electric classic car is wildly expensive and has little to no return. There isn’t really much of a market for repurposed classic cars, although they may pull in some viewers at trade shows and similar events. This is something that’s strictly for car lovers and collectors with deep pockets, but that being said, it’s still a really cool process to see come together.

What About eBikes?

Well, yes and no. There are eBikes with gears, which work similarly to the gears in a standard mountain bike.

You shift as you encounter hilly terrain or rugged roads, with a manual switch or lever, and then adjust your required input power. The bicycle responds accordingly.

You have similar options available for electric bikes. While most ebikes are made with commuting in mind and offer two main speeds, those are designed for flat surfaces and very slight paved inclines. But when you get into electric mountain bikes—and yes, those are a thing—it gets a little more complicated.

Electric bikes do have gears, and some can have multiple gears to help you climb hills, but they have to work in conjunction with pedal assist or full motorized capabilities.You’re in control, so the rider is essentially the transmission between pedal assist, manual power, and when to kick things into gear (that was a cheap pun, but I had to do it).

Why Not Use Full Power in Electric Mountain Bikes?

Power in Electric Mountain Bikes

We’ve all felt this on any bicycle, whether you’re going up the hill of your street or you’re mountain biking in wooded trails: incline pushback.

When the incline becomes steeper, you feel the pedals push back against you and you suddenly need more power to match the same speed you had on flat ground.

Why couldn’t you just use a fully motorized ebike to continue the climb, you might ask. Because it wouldn’t be strong enough, plain and simple. You would end up putting so much physical strain on the motor that it would cause near immediate damage.

Pedal assistance, which is when you throttle and get assistance along with manual pedaling power, encounters similar issues. You could cause damage to the motor if you aren’t careful.

What you should be doing is using your mountain bike’s pedal or full motor assistance to help you on flat inclines so you can recover from uphill struggles. If there’s a hundred feet between where you peaked at the top of a hill and the next incline, this is when you can use it and keep on moving.

You should have multiple gears to help you with manual power, and one or two speeds of electric power to help you during recovery. If you expend all your energy while you’re out on the trails, you don’t want to have a long-winded return home: that’s where the electric motor comes in handy the most with electric mountain bikes.

The Future of Commuting

We know that electric cars don’t have transmissions, but what does this mean for combustion engines if there is a future for them?

Because they can’t have motors that don’t have transmissions based on current technology, it means that energy efficiency is going to be in the hands of electric car and vehicle manufacturers going forward.

For commuting, Sunday drives, or just heading to a weekend party, you’re going to save more energy and utilize cleaner energy with an electric car. Every time you push on the pedal, you’re contributing less and less to pollution than you ever will with a gas guzzler, regardless of what gear you’re in.

Resource:

Noel Joseph

Noel Joseph has been in the world of motor vehicles for a long period. Currently, he is enthusiastic about Electric & Hybrid Motors and is an independent researcher. He advocates for a clean and sustainable future and envisions utilizing his years of experience in mechanical engineering. His new venture here at CompactPower.com is to organize and simplify knowledge on Electric vehicles. He wants to build a space where people can talk about EVs and associated technologies with freedom.