For me at least, I instinctively hit the clutch whenever I hit the brakes. And I think I would also instinctively hit both clutch and brakes if I feel the car spinning out of control.
I’ve never stalled the car after some sort of sudden braking for accident avoidance, but I don’t always remember to shift back into first right away. So I might stall after spinning out and trying to start from fourth, or at least take a few moments to figure out to shift back to first.
I have rebuilt automatic transmissions and most (if not all) have a one way “sprag” clutch which will only let power travel in one direction in certain gears. If a car were to spin out causing the drive wheels to spin backwards then usually the drive wheels will have no way to “communicate” that power back to the engine to cause a stall.
On the other hand I have seen these one way clutches go bad where they will lock up and not do its job. If a spin out were sufficiently violent enough I suppose that the one way clutch could become damaged and send the power back through transmission and the torque converter and stall the engine.
Even if the one way clutch is not damaged the clutch is not perfect and may transfer enough power back to the engine if the spin out is violent enough.
Anecdotally, today one of my co-workers was performing a SMOG check here in the great state of California and to do that you have to run the car on a dynomometer (aka rolling road). For some reason the dynomometer locked up and stopped the wheels very quickly. Literally from about 50 mph to 0 in less than a second. The car had an automatic transmission and the car’s engine stalled. Car was a 2004 Toyota Corolla. Maybe a car with a bigger engine would not have but this one did.
Similar things can happen if you stomp on the brakes while driving fast on snowy roads (without ABS). I think the sprag clutches will stop the engine from actually rotating backwards, but they won’t stop the reverse momentum of the car from bringing the engine down to zero RPMs. I imagine it helps if you’re driving fast enough that the torque converter lock up is engaged, but it might not be necessary.
I’ll take Gary’s word for it WRT an automatic transmission, but I remember having a thread here years ago where the poster asked why his engine stalled after he spun out.
As for a stick shift car, if the driver was driving his own car and had been driving stick for a while, he would almost instinctively (as in, without even thinking about it) hit the clutch as soon as the cop hit him. When you drive stick, hitting the clutch is just “what you do” when something goes wrong. After a while, you don’t even have a choice, I’d imagine as soon as the officer makes contact with your bumper you’ll attempt to speed up and when your rear end starts sliding to the side your left leg will just jump to the clutch. After years of practice you get very good at not killing the engine. Also, when driving stick, with the clutch in there’s nothing you can do with the wheels that’ll have any effect on the engine.
As for why people don’t just keep going, I’d imagine most of them are a but stunned after it happens. They probably don’t realize just how close the officer is or aren’t expecting it. Like others have said, spinning out is pretty traumatic and it take a minute to regain your senses.
Also, if the person isn’t wearing their seatbelt, I’d imagine sometimes the end up not in the driver’s seat anymore.
I have to nitpick, it is in my nature. The purpose of the sprag clutch is to not allow ANY power to be transfered in the opposite direction, as in from the wheels to the engine. My guess is that since the sprag clutch has some friction in it, if you send enough power “backwards” through the transmission it can transmit enough power to stall the engine.
I would also like to add that zero RPMS isn’t necessary to stall an engine. Anything below 500 RPM is enough.
Does this mean engine braking isn’t possible with automatic transmission?
It is only possible to engine brake in a gear that does not have power flowing through the one-way clutch or “circumvents” the one-way clutch. Many transmissions will do this if you put it in low gear which might be represented by the letter L or the number 2 or 1.
The computer that controls the automatic transmission should also engage the torque converter clutch (TCC). Typically the TCC is only activated during light load cruising conditions to increase fuel economy but I BELIEVE it also engages when the transmission is put in low gear and the car is moving at a certain minimum speed.
I know some Mercedes sport cars have the TCC locked in all gears when you set the transmission to sport mode (or whatever the Germans call it) which make for quicker, harder more aggressive shifts.
If you want to feel engine braking on an automatic car put it in low gear and accelerate your car until you reach about 20 mph and release the gas. You should feel some noticeable engine braking.
Many cars have crash sensors that will shut off the fuel pump. Fords, for example, are located in the trunk.
You are quite right. Never thought of that. That might be the final answer to this question.
I rented a Ford Flex a few weeks ago that had an automatic that used engine braking while going downhill. I have no idea how it works, though.
FTW: I was in the blind spot of a truck that PIT-maneuvered me. Not being trained or experienced in recovered from a multi-360 degree spin, my brain froze. (The sterring wheel spun/ripped from my grip, because the tires on the pavement were stronger than me.) I didn’t hit the brakes or the clutch until the car stopped spinning, and lurched forward and struck the central median. It all seemed to happen so fast to me. Watching it on youtube wouldn’t be the same thing.
Also FTW: In this case, my [stick shift] car did not stall. I had to shut off the engine with the key. I had been driving that specific car for 14 years before the accident.
Technically, I don’t think you can do the PIT manuever if you’re the vehicle in front. You just got clipped on your front quarter panel.
Did the fuel pump cut-offs ever really catch on? I always though that was just a Ford quirk.
I said I got pitted. I did not say I did the pitting… I was ahead of the truck by a half a car length.
Here is a picture of the type of truck that pitted me: http://farm5.static.flickr.com/4120/4922113779_b01c25a0e3.jpg
I was on the right hand (non driver) side of the truck.
You said you were in the truck’s blind spot which is generally back and to the side of the vehicle. Hence the confusion. If you were in front of the truck you were not in his blind spot, he was in yours.
[hijack]Under a trucks passenger side door is a blind spot[/hijack]
Usually the PITed driver is busy cleaning out his shorts.
From my limited experience spinning out of control, usually once the car goes into a spin, I’m just trying to bring it to a full stop. Then again I’m not trying to outrun six cops while carrying a sawed off shotgun, a kilo of coke and a tied-up hooker in the trunk (usually).
Post GTA, I might be more inclined to immediately segue into a J-turn and keep going.
I’m not saying it couldn’t happen, but the driver of the truck would have to be an idiot to not see a car on his right side that is a half car length a head of him. :dubious:
I had a '90 Ford Ranger that had the fuel cut-off located under the passenger’s feet.
Also, my dad had a '58 Chevy that had a “GR” on the shift column, indicating “Grade”
It worked pretty good but you had to be going very slow down the grade, say 20 MPH or so.
I have never driven one of those “roach coaches”, so I don’t know how bad the view is from in the drivers seat of one. I am giving the other driver the benefit of the doubt, I was hard to see.
I didn’t start cleaning out my shorts until after the car came to a stop. 
The truck pressed against my driver-side (left) rear panel. This caused my car to start slewing (yawing?) counter-clockwise. I instinctively turned the steering wheel to the right (clockwise) to “counteract” the yaw. After the truck “released” me, I went into a clockwise spin. (One 360, then a 270)
During the spin, the tires were gripping/being gripped by the road, so much so that I could not budge the steering wheel. I was originally headed northbound on the freeway. I don’t know how far north I traveled while spinning, but when the car stopped spinning, I shot forwards (westwards) across three lanes, bouncing off the concrete median barrier, and coming to rest in the number two lane.
I did not think to depress the clutch until I started shooting forward/west.
I struck one other car, and another car struck me (after the spinning was done), to make it a four car accident. (Well, 1 truck, 3 cars.)
I suppose in my case that if I was also the target of a cop chase, the police would have had my car surrounded faster than I could have regained control of it. I think most (non stunt) drivers, when things are spiralling [sic] out of control, instinctively we slow down, or stop, in order to try and regain control. That last is my guess only, though.
