Originally published April 10, 2018; updated January 26, 2022
For reasons numerous and far-reaching, more and more vehicles than ever are hitting Canadian roads with some form of electrified powertrain. Whether a full hybrid, plug-in hybrid, mild hybrid, or full EV, the principle is the same: these vehicles offload some (or all) of the work of the conventional combustion engine to a battery-driven motor.
Using battery-driven motors to supplement or replace a combustion engine is a growing trend that’s sticking around. As it goes with any emerging and growing technology, the nomenclature can be daunting.
Below, we’ll help cut through some of the terminologies swirling around the electrified vehicle marketplace.
Hybrid Electric Vehicle (HEV)
Hybrid, Full Hybrid, Self-Charging Hybrid
What is a Hybrid Vehicle?
A hybrid uses the combined efforts of both a gasoline engine and a battery-powered electric motor to drive the vehicle. The work of driving the vehicle is shared between the two propulsion sources in the most efficient way possible at any given time.
For instance, the electric motor can give the vehicle a boost of power, perhaps while merging or climbing a hill, without burning additional fuel. The vehicle may also be able to drive for brief periods solely on electrical power, with the gas engine turned off. Most can operate in electric-only mode in low-speed situations like parking or idling.
Power for the electric motor is created by a built-in generator and stored in an on-board battery. In a hybrid, all power is generated on board, so it can't be plugged in to recharge.
The nutshell? In a hybrid, a battery-driven electric motor is used to reduce the workload of the gasoline engine, often dramatically, which helps cut down on the fuel consumed.
Though many hybrids have driver-selectable modes that fine-tune operation, the process of blending and switching gasoline and electrical power is fully automatic and handled, often invisibly, by the vehicle’s computer system. At any moment, the vehicle may be propelled entirely by electricity, entirely by gasoline, or by some combination of the two.
Hybrid vehicles need to be refuelled with gasoline, though they typically use much less than their non-hybrid counterparts. Since hybrid vehicles have both a gasoline and electrical propulsion system, their driving range is many hundreds of kilometres.
Because of the added power and torque generated by the hybrid’s electric motor, performance is typically on par, or superior, to an equivalent vehicle with a conventional powerplant.
Mild Hybrid (MHEV)
Mild Hybrid, Light Hybrid
Various GM “eAssist” models, Ram 1500 trucks with "eTorque," Mercedes-Benz "EQ Boost" models
What is a Mild Hybrid?
A mild hybrid sits between a conventional gasoline vehicle and a full hybrid.
A mild hybrid uses a smaller battery and a motor-generator that can both create electricity and help boost the gas engine’s output. They can also be used to run some of a vehicle's auxiliary functions like climate control or be used as a starter/generator to reduce the load on the gas engine.
Mild-hybrid vehicles aren’t capable of all-electric driving and they don’t offer as significant fuel savings as a “full” hybrid, but they’re able to boost performance while reducing fuel use.
When extra power is needed, the motor-generator uses stored electricity to apply torque to the engine, boosting its output without burning additional fuel. Some refer to this as "electric turbocharging." When coasting or cruising, the gasoline engine spins the motor-generator to create electricity that recharges the battery. In a mild hybrid, the gas engine can be turned off to save fuel in more situations like while coasting down hills or when stopped at traffic lights.
In a mild hybrid, drivers get reduced fuel consumption and improved power to a lesser degree than a full hybrid, but at a much lower cost, because mild hybrid vehicles are less complicated, use smaller batteries, and have fewer complex components.
In a mild hybrid, the primary propulsion source is gasoline – meaning that the driving range is on par with a conventional vehicle, or typically, hundreds of kilometres. Mild hybrids cannot be plugged in to recharge.
Electric Vehicle (EV) / Battery Electric Vehicle (BEV)
EV, Full EV
What is an EV?
The EV has no gasoline engine. There’s no fuel tank, no exhaust pipe, and no engine oil to change. These machines are at the extreme end of vehicle electrification: unlike all other examples here, they use a battery-powered electric motor drive system to propel the vehicle 100 per cent of the time.
EVs are recharged via plugging into an electrical outlet or charging station, which restores the onboard battery. This is often built into the vehicle’s floor.
Recharging an EV takes considerably longer than refuelling a conventional vehicle. Depending on the type of charger used and the ambient temperature, a full battery charge can take several hours.
Note that many newer EV models offer a quick-charge function that enables a large, partial boost in battery charge in a short time: perhaps adding hundreds of kilometres of range in just 30 minutes when plugged into a high-output Level 3 fast-charging station.
In an EV, total driving range is typically considerably less than that of a conventional hybrid – though advancements in battery technology are seeing higher EV ranges than ever, with most Teslas offering over 500 km of driving range on a single charge, for example. EV drivers need to be conscious of the availability of nearby charging infrastructure.
However, this infrastructure is growing, and EV charging stations are becoming more and more common at airports, hotels, restaurants, traditional gas stations, rest stops, carpool lots, shopping centres, and other businesses.
EVs typically offer pleasing performance, thanks to the use of high-torque motors. Power delivery is instant and acceleration can be very quick. Many EVs today also offer all-wheel drive. Drivers should be aware that extremes in weather, either very hot or very cold temperatures, can drastically affect an EV's driving range.
In some electric vehicles, like the now-discontinued BMW i3 or Chevrolet Volt, a range-extending gasoline engine acts as a generator to recharge the battery. A range extender is typically used only to power the battery as it runs low, giving drivers the ability to carry on driving without having to stop immediately and recharge. Unlike the engine in a traditional hybrid, a range extender is not connected to the vehicle’s driveline; in other words, it is not directly responsible for driving the wheels.
In a range-extended EV, the priority is on electric driving, and the range extender is only used as a backup. In the BMW i3, the two-cylinder gasoline engine can add approximately 100 kilometres to the vehicle’s range once the battery approaches depletion. These range-extended EVs are not very common.
Plug-In Hybrid Electric Vehicle (PHEV)
What is a PHEV?
The PHEV is a unique vehicle that sits somewhere between a hybrid and a full EV.
In simplified terms, the PHEV works like a regular hybrid, but with a major alteration to its battery. Compared to a regular hybrid, the PHEV battery has a much higher capacity – so high, in fact, that a full battery charge cannot be achieved solely via the on-board generator and requires plugging into an electrical outlet or charging station.
A PHEV is like a hybrid, but with additional battery capacity for extended all-electric driving. With a fully charged battery, a PHEV can typically drive for somewhere in the neighbourhood of 25 to 50 kilometres solely on stored battery power. Once that range is used up, the vehicle works like a normal hybrid, until it is recharged again.
On short trips, the PHEV operates like an EV, using no gasoline. But, unlike an electric vehicle, the PHEV can revert to regular hybrid operation once its EV range is depleted, using gasoline and self-generated electricity, for hundreds of kilometres of additional driving.
In a PHEV, drivers get the benefits of all-electric motoring on shorter trips and commutes, and full hybrid driving range after that. Even if you’re unable to recharge the PHEV for an extended period of time, the vehicle will still function fully as a conventional hybrid. Charging your PHEV reduces its fuel use, but it’s never mandatory.
With a fully charged battery and a full tank of fuel, PHEV driving range is on par with a conventional vehicle.