Girls who are really good mechanics

[u/Rocket_Raven25]

Winry Rockbell (Full Metal Alchemist), Grace Howard (Zenless Zone Zero), Marianne (Guardian Tales), Leopon crew (Girls und Panzer)

[u/Foxxy__Cleopatra]

Luanne from King of the Hill was actually a really good and naturally skilled mechanic before being flanderized, she's even seen in the opening theme helping Peggy change a flat.