Engineering Explained does a lot of real math on car related topics while also being interesting. https://youtube.com/user/EngineeringExplained

Michel Van Bizen has hundreds (thousands?6 of university level lectures on many topics science and math: https://youtube.com/c/MichelvanBiez

Discovered that channel trying to understand all modes of heat transfer through windows. Covered under thermodynamics. https://youtu.be/r3tC-ocdVoQ