[dukeofdoom]

It's possible it might actually be more reliable long term, once the technology matures. For example, in cold weather the gas engine might heat the battery for better battery performance, maybe even extend its life if it prevents it from being drawn down too much. The gas engine, would also likely last longer since its not used for daily commutes.

"In many PHEV systems, there are different modes:

Electric mode (EV mode): The vehicle runs purely on the electric motor(s) and battery until the battery depletes to some extent.

Hybrid/Parallel mode: Both the petrol engine and electric motor(s) work together to drive the wheels, especially under high load, higher speeds or when battery is low. Ithy

Series mode (in some designs): The petrol engine acts only as a generator to charge the battery or power the electric motor(s), and the wheels are driven by the electric motor(s).

For the BYD Leopard 5 (and many BYD PHEVs) the petrol engine can drive the wheels (i.e., it is not purely a generator). It is part of the drive system, especially when high power or long range is needed.

At the same time, it likely can assist with charging the battery or maintaining battery state of charge (SOC) when needed (for example, to keep the battery at some reserve level or in “save” mode). User-reports show that the petrol engine will kick in to support the electric system, charge the battery, or assist the drive under certain conditions" -