BYD476ZQA

BYD's 1.5 turbocharged four — in the Han, and under the DM-i badge in the Qin and Song.

In most of the cars it is fitted to it is not driving the wheels. The DM-i cars are plug-in hybrids in which the engine spends most of its life as a generator, so a complaint about power, response or gear selection on one of these is almost never a question about this engine — it is a question about the hybrid control strategy, which byd-dm-i covers.

Where it does drive the wheels it is a conventional modern turbo four: direct injection, a chain, and a turbocharger whose life tracks oil condition. Intake-valve carbon at mileage is expected rather than a fault, and it responds to cleaning.

The engine runs far less than the odometer suggests on a plug-in, which cuts both ways: less wear, and more of the trouble that comes from an engine that rarely reaches temperature — condensation in the oil, and fuel that has sat.

English-language documentation is thin and BYD's own service literature is the only reliable source for procedures.