That was the second possibility he raised. I was responding to the first.
I pulled out my Bosch Automotive Handbook (3rd Ed.). The European requirement for “residual braking effect” - that is, the brake capacity remaining when power assist devices are disabled - is that a passenger car must be able to achieve a decel of at least 1.7 m/s^2 (about 0.17 g’s) with a pedal force no greater than 700 N (157 pounds). I presume the US standard is similar.
When spec’ing brakes for a vehicle, no manufacturer will waste money to exceed this requirement by more than a small margin. And A car with a decent V6 in it will provide considerably greater acceleration than this, particularly in lower gears. Which means, IOW, if you can’t find a way to get the transmission out of gear or shut off the engine, once that thing goes WOT, you’re screwed.
Okay - I tried it and found that I could lock up the brakes (albeit with considerable force needed). So it’s a definite case of YMMV.
FWIW back when Audi was getting screwed on sudden acceleration, Mercedes was also accused of this. The NHTSA actually went so far as to open an investigation. MBZ showed up with one of the model cars that was being investigated. They took a NHTSA employee and put them into the car. They accelerated up to about 25 MPH and putting one foot on the gas and the other on the brake they put both feet to the floor.
the car stopped.
they repeated at freeway speed.
The car stopped.
MBZ said “Any questions?”
NHTSA said “Never mind”
The investigation was closed.
With the vacuum remaining in the accumulator, and a single, hard stomp on the brake pedal, this is entirely plausible. But if you hold the gas pedal down and pump the brake a few times to waste that built-up vacuum, I have my doubts.
(IIRC, the Audi problem was ultimately attributed to an unusual placement of the accelerator and brake pedals, resulting in pedal misapplication. Pedals were just slightly closer together, or both farther left or right, than on most other cars, enough to reportedly confuse drivers in a panic situation.)
Holy shit, what a confusing mess. They deserve to get sued for having a shift lever that looks like a brain-teasing puzzle.
You find that confusing? I hope for your sake you never drive a Jaguar.
Except for the “sport mode,” that’s not a terribly unusual layout for modern automatic trasmissions (although, come to think of it, I’ve only seen the gated automatics in European brand cars.) It actually surprisingly well, in my opinion.
Here’s a Mercedes shift lever, for example.
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2008-on automatic Hyundais all have gated shift actions.
Here’s the 2011 Elantra, for example.
Oh, and here’s the classic Jaguar J-gate (though that one is a modern sequential 'box, not a regular auto), in case you’re wondering what I meant.
Do any of you guys own a Camry? I have a 2005 Camry, and I’ve always assumed the revving was just the way the engine worked. Sometimes from a stoplight, the Camry (automatic) would rev to the max very quickly and then drop down back to the normal level.
So some/all/most modern automatic transmissions have no physical connection from the lever to the transmission?
:eek::eek::eek:
Some.
I know that’s the case on the Toyota Prius hybrid, and it sounds like some of the other Toyotas, too.
Being of a cynical nature, I would have asked them to repeat this with a random car pulled off a nearby Mercedes-Benz dealers’ lot, rather than a specific one they had brought with them (and maybe specially modified to enhance the brakes).
Rather like Consumers Reports, which buys the cars it tests from various dealers anonymously, vs. the automotive fan magazines, which test prepped cars provided free to them by the manufacturers – Consumers Reports always seems to find problems that the other magazines don’t.
Eh? The regular auto rags often end up testing pre-production versions, which are often less well put together and more buggy than production models.
You put a Prius in park by pushing a button, not by moving the stick, which I’m still getting used to.
Yes AFAIK modern cars have a rev limiter. It will hit redline, the fuel supply will cut, RPMs drop momentarily, lather, rinse, repeat.
Say the brakes are jammed or for whatever reason don’t work. Does shifting from Drive to Neutral at a high speed, without using the brakes, strip any gears? (Pardon my mechanical ignorance.)
No - although it’s not advisable.
Shifting back into gear certainly would.
Automatic transmissions should be able to deal with Drive->Neutral and Neutral->Drive shifts while moving just fine. However while redlining the engine the N->D shift may be a problem.
“Redlining” meaning what?