I find it hard to believe that the brakes wouldn’t simply overpower the engine. I’ve always taken it as an article of faith that the brakes of ANY car can easily overpower the engine. One piece of evidence is regularly published in car magazines–the 0-60 times (acceleration) are always longer than the 60-0 times (braking). Similarly, when one car mag posted their comparisons of 0-100-0 times, the braking time was always much shorter.
Another example comes from my misspent youth, when I had a job ‘prepping’ vehicles (washing the cosmoline they were shipped in) at a local car dealership; when we got a batch of cars destined for use as cruisers for our State Police, we staged impromptu exhibitions of the braking systems might. We would plant our feet firmly on the brake pedal and simultaneously press the accelerator until the rear wheels began a smoky burnout, all at 0 miles per hour. And this was with a honking 428 Police Interceptor engine, not a Prius 4-banger.
Now, I grant you that there is a lot of kinetic energy embodied in a speeding Prius at 90 mph, but I find it hard to understand that the brakes wouldn’t eventually overpower the engine. Unless there’s no longer a mechanical connection between the brake pedal and the brake master cylinder (which I find hard to understand), even without power assist, an average sized person should be able to simply ‘stand on the binders’ and gradually bring their racing steed under control.
And on the subject of power assist, I read in other posts that power steering would continue to work, since the engine and, presumably the power steering pump, would continue to be driven even with the ignition switched off. I’m not sure this applies to vehicles like my Honda Fit, which has electrically-assisted steering; switching off the ignition would likely disable the power assist. Even so, I can recall driving vehicles where the belt driving the power-steering pump broke and I was still able to control the direction of the car (power-steering by Armstrong…).
So, I hafta think that, if something goes amiss in a car’s ECM, and they do get some unexpected acceleration at an inopportune time (say the middle of a freeway off-ramp), it could possibly lead to a crash. But nowhere in my wildest imagination can I think of a set of circumstances where a person’s Prius should be out of control for 20 minutes, despite their best efforts to bring their car under control.
Boy do I agree! BTW, I drive a Lexus 450h and got so tired of hearing my brother and sister tell me the accelerator would get stuck that I floored it one day when they were in the back seat and told them it had! Of course, they didn’t believe me. So I released the accelerator and ---- it stuck to the floor!! We sped up for a minute or two while I tried to release it and they kept laughing like hyeanas in the back, then I shifted into neutral and - this is key to a hybrid like the Prius - the engine immediately STOPPED. (As it always does when the battery is charged and the car is not in gear.) It was easy as pie to bring the car to a normal stop and find the problem, which was my foot has shoved the floor mat over the accelerator pedal when I floored it.
So stopping a hybrid even if it did “run away” is a pretty simple task that does not require a police cruiser beside you.
After all of the attention to floormats and accelerators someone still managed to get one stuck. Yes, in this case it is the drivers fault, and luckily no one was hurt in the two minutes. But if it is a software or electronics problem causing the most serious accidents, (as is looking increasingly likely), this situation and it’s remedy probably won’t work, as evidenced by testimony of survivors. No recall will nullify stupidity, by the way. Oops, come to think of it there is one…