Always wanted to know this, always been afraid to Google it because I figured it would report me for self harm or something like that.
So, 1. What would happen if, while driving on the highway at highway speeds, you grab the gear shift knob and put it in park? Would it just lock up all the wheels or what?
And 2. What would happen if, also while driving on the highway, at highway speeds, you turn the car off (turn the key and remove it)?
I feel like both should be impossible while the car is in motion. But somehow I don’t think they are. And to a gearhead, these are probably really stupid questions. But as someone who barely understands how cars do what they do… I’m curious.


My driving instructor included #2 in the lessons a decade (or 2) ago
You lost power steering and power breaks, so car was heavy but steerable. Goal was to put it back in neutral, start the car, and drive off
TLDR, keep calm and carry on.
Sounds like a good instructor. I’ve had my car shut down twice (different cars) while driving on high speed motorways and something like this would’ve been handy
My parents had an old car with a manual transmission, no power steering, no power brakes, and no steering wheel lock. My dad and I had a game where we would shut off the engine about 1/4 mile from home and coast all the way into the garage. Whoever could coast the furthest without speeding or needing to restart the engine would get bragging rights. If you did have to restart the engine, you got points for putting it in gear and clutch starting rather than using the key.
I wish I got along that well with my dad in a car! He tried teaching me how to drive in two different occasions and after ending up in arguments both times, we decided it was best I learned from a professional instructor and have him removed from the equation. We get along well otherwise, just not with a steering wheel involved.