Key Differences and Similarities Between Electric and Internal Combustion Engine Vehicles

The advent of electric drivetrains marks a significant transformation in the automotive industry. As a result, many components of conventional internal combustion engine (ICE) vehicles are irrelevant to electric vehicles (EVs). This article highlights the key differences and similarities between ICE and electric vehicles.

What's New?

We will begin with a fundamental component unique to electric vehicles: the high-voltage battery. This battery serves as the equivalent of a fuel tank in an ICE car, storing electrical energy that powers the electric motor.

Another new component found in electric vehicles is the electric motor, which converts electrical energy into mechanical energy for propulsion. However, the electric motor and high-voltage battery operate using different electrical currents. The battery supplies DC (direct current), while the electric motor requires 3-phase AC (alternating current).

To bridge the gap between these components, an inverter acts as an “interpreter.” This device converts DC from the high-voltage battery into 3-phase AC for the electric motor during operation. Conversely, during regenerative braking, the inverter converts AC back into DC to recharge the battery.

The efficiency of the inverter significantly impacts the overall efficiency of the electric vehicle. Additionally, the onboard charger serves as another “interpreter,” converting AC from the power grid into DC for battery charging. When using high-power DC charging, the onboard charger is bypassed.

Heating methods differ in electric vehicles as well. Electric vehicles utilize PTC heaters (Positive Temperature Coefficient) and heat pumps, unlike ICE vehicles that can leverage wasted thermal energy from their engines to heat the cabin.

The DC/DC converter is another novel component in electric vehicles, responsible for converting high-voltage DC from the battery to 12V for low-voltage systems like lights and infotainment.

Finally, the charging socket is a distinctive feature of electric cars.

What's Different?

Both ICE and electric vehicles employ air conditioning compressors, but their power sources differ significantly. In electric vehicles, the air conditioning compressor is a high-voltage device powered by the battery, whereas in ICE vehicles, it is a mechanical component driven by the engine's crankshaft. This mechanical reliance can result in a noticeable power loss when the air conditioning is activated in ICE vehicles.

Both vehicle types use gearboxes, but electric vehicles typically feature simpler transmission systems, often with a single gear ratio. In contrast, modern passenger ICE vehicles commonly utilize 9-speed automatic transmissions.

The braking systems also reflect a contrasting philosophy. In most electric vehicles, pressing the brake pedal engages the electric motor as a generator, providing initial braking while recharging the battery—this is known as regenerative braking. If greater stopping power is required, conventional hydraulic brakes activate. Conversely, ICE vehicles consistently rely on hydraulic brakes each time the driver engages the brake pedal.

Moreover, electric motors require minimal maintenance, typically having only two moving parts, while internal combustion engines possess numerous moving parts—an average 4-cylinder engine has at least 40 components that necessitate regular maintenance, such as oil and fuel filter changes.

What's the Same?

Despite their differences, electric and ICE vehicles share similarities in suspension, wheels, and tires. The same suspension architectures are often found in both vehicle types.

Electric vehicles built on ICE platforms typically maintain the same suspension design as their counterparts. Dedicated electric vehicle platforms often employ independent suspension systems, such as multi-link, double wishbones, and McPherson struts.

Suspension components, including shock absorbers and springs, are adjusted in electric vehicles to accommodate their additional weight.

Tire designs are also largely comparable between the two vehicle types. Low rolling resistance tires are available for both ICE and electric vehicles. While earlier electric vehicles featured unique “aero” wheel designs, many modern ICE models now incorporate similar aerodynamic wheel designs to minimize drag.

The steering systems employed in both vehicle types share similarities as well. Both are equipped with electromechanical systems capable of supporting advanced driver assistance features like lane assist and autonomous parking.

Conclusions

In conclusion, the primary distinctions between ICE and electric vehicles stem from their fundamentally different propulsion systems, which necessitate unique components. However, recognizing the similarities between these two types of vehicles is essential, as many parts remain consistent despite the differences in propulsion. This commonality is beneficial, as it can aid in reducing costs and facilitating the widespread adoption of electric vehicles.