If you’ve been following electric cars throughout the years, you may have one question on your mind: are electric cars direct drive? This is a fair question and one that deserves looking at what direct drive is, how it would work with an electric car, and what we could possibly expect in the future.
We’ll cut to the chase and let you know that, no, electric cars aren’t direct drive. Several years ago, the EV world got pretty excited about the world’s first direct-drive electric car—and while dreams have since then fizzled out, we shouldn’t forever do away with the idea that direct-drive and electrification might mix.
It seems as if the simplicity of an electric vehicle would be compatible with the simplicity of direct drive. Not only that, but the perceived environmental and economic benefits would be of interest to manufacturers and consumers alike.
However, at this point, the complications that would arise from direct drive are too much to bear. So, while most electric cars favour a single gear transmission, the widespread adoption of direct drive doesn’t seem so likely at this stage.
Direct Drive: EVs vs Gasoline (ICEVs)
One of the main reported differences between electric vehicles and an internal combustion engine vehicle (ICEV) is a simple one: they just feel different. When you hop behind the wheel of an electric car, you’ll notice the difference right away.
Electric cars are smooth. They’re quiet. They feel like they glide. What’s the reason for all of this? Well, they’re built differently.
Electric cars have fewer parts than their petrol-fuelled counterparts—namely, multiple gears.
In an ICEV, a multi-speed transmission is necessary. In order for torque and power to contribute to acceleration, it’s most efficient when moving through narrow bands of engine speeds.
However, in an EV, almost all torque is generated at low speeds. So, while an EV, in theory, could have several gears, they aren’t necessary. Not only are they not necessary, but they would add additional complexity in the form of weight and friction to an otherwise very simple system.
Does this mean that electric cars have direct drive? Even with all of the perceived advantages, direct-drive still isn’t suitable to roll out for most electric cars.
Electric Cars Don’t Need Transmissions
Because of the ability of electric vehicles to reach torque and speed without a lot of moving parts, there isn’t a need for them to have transmissions. While recent reports indicate that EV manufacturers are beginning to consider using two-speed gearboxes (like the Porsche Taycan), all other production EVs operate off of single-speed transmission.
Most manufacturers are content with this type of motor. With just a single gear, it’s lighter and cheaper than a direct drive motor.
What is Direct Drive?
Simply put, direct-drive means a type of transmission that uses torque without the need for a gearbox. There aren’t a lot of gears connecting, so cruising at a higher gear is easier for the vehicle. When you think about it, there’s really no simpler system. The motor turns and the wheels turn as a result—all possible without the need for a bulky transmission.
So, What Does This Have to Do with Electric Cars?
If you’ve spent some time exploring the electric car world, you may have heard of the Mitsubishi Lancer Evolution that made headlines in Australia a few years ago (2013). It was Evans Electric’s first attempt at a direct drive electric car. The four-door sedan boasted 5,000 Newton-meters of torque, impressive safety features, and exceptional performance metrics.
At the time, Evans Electric was hailed as one of the most brilliant car manufacturers ever. Their beautifully simple idea to skip the transmission and gears required in a petrol engine was considered nothing short of revolutionary. By attaching the electric motor directly, each wheel would be powered much more efficiently.
Not only would this improve the car’s efficiency and ecological footprint, but it would provide a much-needed solution to the EV battery conundrum. At the time, the batteries in electric cars hadn’t undergone the technological advancements of today, and their range was much more limited.
When you look at first glance, the benefits of using direct drive in an electric car are nothing short of ground-breaking and revolutionary—just the sort of innovation an electric vehicle needs.
Advantages of Direct Drive
Because of its simplicity, efficiency, and reliability, direct drive is considered one of the most revolutionary innovations in the automotive world. Without a transmission required, the number of moving parts are much less, too.
The fact that repairs and replacements are few and far between makes direct drive much more environmentally, too. Without a gearbox, some of the most complex and environmentally intensive replacement parts of a car are removed.
Not just that, but the efficiency beats a gear-driven system, particularly in terms of the amount of energy. Transmission can be responsible for up to 10% energy losses, simply due to mechanical friction. With direct drive, there is no transmission, no gears, and no energy wasted.
For anyone looking to reduce their carbon footprint, an electric car with fewer parts, more efficient performance, and fewer repairs needed makes all the sense in the world.
Or does it?
Why did Electric Car Manufacturers Give Up?
While there are some perceived benefits to using direct drive in electric cars, one significant concern is the abuse that they would have to withstand. Using direct drive transmissions on flat highway roads wouldn’t present too many difficulties—but other conditions may present severe issues.
Imagine this: You’ve got a simple and direct drive system in your new Tesla. You’re off for a drive and hit a pothole. You continue driving down a bumpy road and your wheels continue to bounce all over the place. The unsprung mass in the wheels would not only impact performance, but any excessive damage could reduce any of the environmental, economic, and efficiency benefits of direct drive.
Directly driven axles may be simple in theory, but they can pose some pretty complex issues. Repairing an electric motor shaft can be expensive and rather difficult—which minimizes some of the benefits of direct drive in the first place.
But this doesn’t mean that electric car manufacturers have totally given up. DANA has produced the TM4 SUMO, high torque powertrain system that enables commercial vehicles and buses to use direct drive technology, combined with hybridization and electrification.
This type of technology has become widely adopted over recent years. Next time you hop on an electric or hybrid city bus in Australia, Canada, the US, China, or much of Europe, you may be in one using direct drive.
It may appear at first glance that dreams of electric cars with direct drive motors are over. In fact, with cars like the Porche Taycan exploring a two-speed gearbox, we’re actually moving in the opposite direction. The simplicity of a direct drive seems to match well with the simplicity offered by an electric vehicle. But, when it comes down to it, it appears the potential cost and mechanical complications are too much for large scale adoption.
However, this doesn’t necessarily mean one more nail in the coffin for electrification and direct drive technology. We’re seeing direct drive systems in commercial and passenger vehicles. Who knows? With the electric car world evolving all the time, we could see another Mitsubishi Lancer Evolution appear again in the future, too.