Hi, I doubt if a specific word or title exists for this. But, I've heard "Car geek". If you really know about all the things related to the cars and engines, you must be a car technician. Therefore, I don't think we have something specific. In general there is an expression "A know-it-all" which means someone who knows (or thinks that know) all the things about everything. Ex: A know-it-all person. علامه دهر

Where I live in the U.S., someone who is really into cars is called a "Gearhead".

omniscient یعنی همه چیز دان فک کنم این کلمه آیه که دنبالشی ولی یه کلمه دیگه هم داریم با یه معنی تو همین مایه ها ولی برای مسخره کردن کسی به کار‌میره know it all person

There are many, but here are 2: - enthusiast - hobbyist

the same word can be used for a person whom loves classic cars (like me for example) I am a classic "hot rod" car buff