On Tue, 2 Feb 2010, Michael Porter wrote:
> Umm, that little thing known as kinetic energy? If you're going sixty, the
> brakes can dissipate that energy reasonably quickly as heat--as long as
> there's no additional energy being added. However, if that engine is going
> full chat and producing near peak horsepower, adding to the kinetic energy of
> the vehicle as the brakes are trying to subtract from it, it's a losing
> proposition. Physics wins.
>
> e_sub_k=m * v-squared
There seem to be a bunch of different scenarios getting confused here.
Some people, like Michael, are talking about a situation where the engine
is running wide-open. Maybe it's me, but that seems highly unlikely.
I drive fast, on the street, and I find myself using full-throttle almost
exactly never. The only times I've been there in my F150 are on race
tracks ( recon runs to check an autocross course, and running out to
retrieve broken/stuck racecars at Autobahn and various frozen lakes in
Michigan ). Now granted, a fullsize pickup isn't very sporty, but I drive
my wife's 295hp Saab sometimes, and there's no remotely legal situation
where you can get much beyond half-throttle. It was very difficult to
reach WOT in any marginally-powerful sporty car that I've owned.
It seems outrageously unlikely to me that there a bunch of people
driving...
. Certain 2009-2010 RAV4
. Certain 2009-2010 Corolla
. 2009-2010 Matrix
. 2005-2010 Avalon
. Certain 2007-2010 Camry
. Certain 2010 Highlander
. 2007-2010 Tundra
. 2008-2010 Sequoia
...who are getting the pedal to the metal very often.
So if you _aren't_ mashing the gas, I still think the vehicles brakes
will stop you. And in several of those vehicles, like a 132hp 2010
Corolla, I'm still betting on the brakes even if you are.
Fwiw, the same Press Release from Toyota ( where I got the vehicle list
) says;
"In the event that a driver experiences an accelerator pedal that sticks
in a partial open throttle position or returns slowly to idle position,
the vehicle can be controlled with firm and steady application of the
brakes. The brakes should not be pumped repeatedly because it could
deplete vacuum assist, requiring stronger brake pedal pressure. The
vehicle should be driven to the nearest safe location, the engine shut
off and a Toyota dealer contacted for assistance."
--
David Hillman
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