> I have a slightly different take on engine braking.
> I've seen some folks say that it is a useless feature, and some who have
> found it quite useful.
> My take is this:
> I own a 2 seat, Piper Tomahawk aircraft that I land on a 2000 foot runway
> in Virginia. On landing, I cross the threshold at about 67 MPH, always
> stop in 2000 feet, and have had practically no brake wear. I've made
> hundreds of landings, and, as far as I can tell, my brake pads will last
> for many years to come before needing replacement. The secret is that,
> whenever possible, I make use of full flaps on landing. In addition to
> creating more lift at landing speeds, they also add significant drag to
> the airflow. I also use the body of the plane, in nose up attitude, to
> create even more drag. Thus, I use air drag to do almost all of my
> braking for me, and only use the actual brakes at the very end, just
> before turning off of the runway.
> I view the engine brake in the Prius the same way I view my landing
> technique. The more I can stay off the brake pedal, the longer those pads
> and rotors will last. I realize that the brake pedal is, in part,
> regenerative. However, I cannot tell exactly when it stops being purely
> regenerative and when it begins to be mainly pads and rotors. With the
> engine brake, I know it is fully regenerative, and no brake pad is being
> wasted. Thus, I've begun to use the engine brake often and early, to
> bleed off some of the energy before having to apply the brake. In some
> instances, you can bleed off all of the energy, and not have to hit the
> brake at all. This should make for much longer brake life, at the slight
> expense more back pressure being applied to the gears in the transmission.
> It would be nice if Toyota could add to the energy screen a dual bar
> graph, which would display the percentage of braking done by regeneration
> and the percentage being done by the brake pads while braking. This would
> certainly help in extending brake life.
> Paul
I'm no expert, but I've come to believe the braking is almost entirely
regenerative under normal conditions. Some people have the Coastal
Electronics friction brake indicator light and they can tell you more about
it than I can. We know it reverts to friction brakes at low speed, when the
stopping called for is harder than the regen can do, when the battery is
"full" and when going over bumpy surfaces. Otherwise, I don't think the pads
get much use.
Using the B setting will definitely burn off energy, but it will do that
whether it needs to be burned off or not.
Mike
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> I've seen some folks say that it is a useless feature, and some who have
> found it quite useful.
> My take is this:
> I own a 2 seat, Piper Tomahawk aircraft that I land on a 2000 foot runway
> in Virginia. On landing, I cross the threshold at about 67 MPH, always
> stop in 2000 feet, and have had practically no brake wear. I've made
> hundreds of landings, and, as far as I can tell, my brake pads will last
> for many years to come before needing replacement. The secret is that,
> whenever possible, I make use of full flaps on landing. In addition to
> creating more lift at landing speeds, they also add significant drag to
> the airflow. I also use the body of the plane, in nose up attitude, to
> create even more drag. Thus, I use air drag to do almost all of my
> braking for me, and only use the actual brakes at the very end, just
> before turning off of the runway.
> I view the engine brake in the Prius the same way I view my landing
> technique. The more I can stay off the brake pedal, the longer those pads
> and rotors will last. I realize that the brake pedal is, in part,
> regenerative. However, I cannot tell exactly when it stops being purely
> regenerative and when it begins to be mainly pads and rotors. With the
> engine brake, I know it is fully regenerative, and no brake pad is being
> wasted. Thus, I've begun to use the engine brake often and early, to
> bleed off some of the energy before having to apply the brake. In some
> instances, you can bleed off all of the energy, and not have to hit the
> brake at all. This should make for much longer brake life, at the slight
> expense more back pressure being applied to the gears in the transmission.
> It would be nice if Toyota could add to the energy screen a dual bar
> graph, which would display the percentage of braking done by regeneration
> and the percentage being done by the brake pads while braking. This would
> certainly help in extending brake life.
> Paul