I have had a scary experience a couple of times in my first 1500 miles with the X (my first Tesla, third electric vehicle) and am wondering if it is some kind of hidden feature of the emergency braking system: a car quite a ways in front of me suddenly stops for some reason, so I hit the brakes rather hard myself (even though there is quite a bit of room between him and I) as a precaution...but the Tesla doesn't slow much at all. I start getting worried as I quickly approach this stopped (or soon to be stopped) car in front of me and really begin hitting the brakes hard, but the Tesla is taking a rather leisurely pace at slowing down. I panic and hit the brakes as hard as I can as I approach the car in front, hear some warning chimes as I begin thinking I'm going to hit this vehicle, and then emergency braking kicks in and I stop just in time.
Is the car trying to give me a heart attack, ignoring my hard braking because it doesn't detect an imminent collision, or is something broken? I'm tempted to try looking for an empty stretch of road and try just stomping the brake pedal as hard as I can to see if it will let me brake hard for no reason at all, as a test. Keep in mind autopilot was OFF in both situations (I didn't purchase it, and haven't upgraded to it yet). I haven't changed any emergency braking settings since picking up the car, so I assume they are set to default values.