Some people may view reliability purely as the susceptibility of the car to breaking down, or how likely it is to suffer from a mechanical issue. Others may take a broader approach to reliability, and also consider how consistently the car’s software or app-based features function as intended. 

    Do fewer moving parts equate to greater mechanical reliability?

    A key argument for why an EV should be more mechanically reliable than a combustion engined car is that an EV is simpler and has less moving parts than its combustion equivalent, and thus less points of failure or things that can go wrong. There are no moving pistons, camshafts or turbochargers in an electric vehicle. With regard to the drivetrain, combustion vehicles typically use far more complex transmissions and gearbox designs that involve multiple clutches, torque converters and other parts, compared to the simpler one or two-speed gearboxes that most EVs use. Moreover, electric vehicles also have less consumables such as coolant, fluids and oil that may need to be replaced during a service.

    Theoretically, this means that an EV should break down or suffer from a mechanical issue less frequently than a combustion engined equivalent. With less parts that move, there should also be a correspondingly lower level of wear and tear, which should equate to cheaper maintenance costs. 

    The reality is murkier. Much like how some car brands are widely perceived to build more reliable vehicles than others (despite using the same basic combustion engine technologies), the reliability of an electric vehicle is likely to vary by OEM. This is where the quality and thoroughness of the overall vehicle development process comes into play. OEMs have their own standards of testing a vehicle, and may also put different levels of effort into designing and engineering a quality car. These same differences are likely to continue to be the case for electric vehicles.  

    Software: Another area to watch

    Another characteristic of modern EVs is that they tend to be software defined vehicles. Software is used to control everything from the infotainment and HVAC system (heating, ventilation and air-conditioning), to thermal and battery management systems that determine whether they need to be cooled, or what pre-conditioning is required for faster charging. Software also allows an EV to be a connected car, and to be controlled by an app on the user’s smartphone and interact with other devices.  

    This means that software quality and reliability will also become an important contributor to overall vehicle reliability. In the future, it is plausible that the majority of problems that owners face will be software issues. The nature of software and its ability to be easily modified means that these types of issues may be more frequent, but can also be resolved more easily and conveniently through an over-the-air update (OTA update) rather than requiring a trip to the mechanic. Of course, OEMs will also need to incorporate stringent bug-testing and validation processes in their software development cycles to ensure that an OTA update does not introduce further problems into a car.