I don't know that I'd classify car engine production as 'heavy manufacturing'

You need to smelt and cast iron/aluminum for engine blocks, which is energy intensive.

Pretty sure those don't run on electricity.

Electrical aluminum smelters are pretty common. They consume an insane amount of power, 13 to 15 MWh / ton! (to produce aluminum from raw ore).

For foundries the picture is a bit better, for instance:

https://www.strikowestofen.com/aluminium-holding-furnaces

There are also gas fired ones and various special purpose furnaces (recycling, for instance).

Energy isn't just electricity. Could be gas as well.

A car is not just four wheels strapped to an engine.

If you add a monitor, you can call it Tesla. /s