Don't tell anyone, but I pretend to know stuff about engines to sound like a car guy and impress people.
What is your reason for wanting to fake car knowledge?
I think people find me stupid if I can't answer questions about cars.
Many people make assumptions about others, especially considering toxic masculinity. Pretending to know about cars in order to impress people is understandable as long as you don't give them advice that could affect their safety.
I'm just talking about what I know, it's not like I'm giving them advice.
You might be able to fake it with somebody who knows nothing about cars, but your lack of knowledge will be obvious to anyone halfway mechanically inclined. Stick to talking about what you know, even if it's just ballet and crocheting. You'll impress a lot more people, especially the ladies.