What is the difference between PHEV and MHEV?
4 Answers
PHEV and MHEV differ in their positioning: PHEV is a plug-in hybrid electric vehicle; MHEV is a mild hybrid electric vehicle. The PHEV is a compact urban SUV with body dimensions of 4510mm in length, 1852mm in width, and 1708mm in height, and a wheelbase of 2650mm. In terms of power, the MHEV is equipped with a 1.5L naturally aspirated engine and a 130kW electric motor. The engine has a maximum power output of 71kW and a maximum torque of 120Nm, with the maximum power achieved at 5500 rpm.
I did my homework on these two hybrid types before buying a car. Simply put, a PHEV is like a rechargeable electric mule hybrid—it can run over 50 km on electricity alone, and with a home charger, your commute barely uses any gas. But an MHEV is essentially still a fuel-powered car, relying on a small motor to assist the engine at startup and storing braking energy in a small battery, with no ability to charge or drive in pure electric mode. In practice, a PHEV drives quietly like an electric vehicle at low speeds, only burning fuel when the battery runs out. An MHEV feels almost the same as a regular car, mainly saving some fuel and offering smoother auto start-stop in traffic. If you have easy access to charging, a PHEV’s operating costs are significantly lower.
I think the main differences lie in the battery and usage patterns. PHEVs have large batteries similar to pure electric vehicles, can be recharged via plug-in, and can easily run 70-80 kilometers on pure electric power, making them suitable for people who can install charging piles at their workplace or residential area. MHEVs, on the other hand, have small batteries comparable to a mobile power bank, only assisting the engine during acceleration and storing energy recovered from braking for later use, with no option for plug-in charging. In terms of actual usage costs, PHEVs can cost just a few cents per kilometer when charged during off-peak hours at night, while MHEVs at best save about 10% in fuel consumption compared to conventional fuel vehicles. Current policies also differ significantly; in cities like Shanghai, PHEVs can obtain green license plates, whereas MHEVs are generally treated the same as conventional fuel vehicles.
From a technical perspective, the core difference lies in the driving method. The PHEV's electric motor can independently drive the wheels, and with a sufficiently large battery, it can function as an electric vehicle. The MHEV's motor is merely an assistant, only capable of supporting the engine and unable to operate alone. Charging is another key point: PHEVs must regularly find charging stations to replenish the battery, while MHEVs rely entirely on the vehicle's own energy recovery. In terms of usage costs, electricity for PHEVs is about 80% cheaper than fuel, whereas MHEVs save only about 1 liter of fuel per 100 kilometers. Without home charging facilities, purchasing a PHEV is like taking on an unnecessary burden.
