The "B", as I understand it, is a type of engine brake, similar to a Jake Brake on big trucks, without all the ear splitting noise. When I took my 07 TCH in for it's 5000 mile check up, I was told never to use the "B". It could ruin the engine or the transmission or the electric drive motor or some such nonsense. He really didn't seem to know why or at least that is the way it seemed to me; he sounded like he was trying feed me a line. Why would a mechanic say something like that? Why would Toyota make it so readily available if you shouldn't use it? That was one of my favorite features, next to all my other favorite features.

I LOVE MY TCH and I don't want to damage it.