This was always my assumption. I mean, higher RPM's are just that, I never really considered why they were higher (ie, exhaust brake engaged or whatever).

Say I had someone next to me in an identical truck, just pressing a brake pedal, vs. me revving 1900 RPMS to help slow the truck....?

Matter of fact, considering we are talking a 6 speed, what if one driver puts the truck in neutral and applies the brakes normally, the other stays in gears (down shifting) with the EB on as he slows.

Dunno.

 

Although, I'm somewhat confused at what some are referring to as "on". I mean, mine stay off (6 speed) when rowing up through the gears. Once I get up to speed I almost always flick it on. This way, weather it's slower traffic or actually slowing to approach a complete stop, it does it all on it's own.

I guess if someone wanted to get really silly with it, having that flapper in there is probably not great for exhaust flow over all.

 

The difference is that you are not reving to 1900 rpms by giving it fuel. The momentum of the truck pushing the engine is what is reving it. The computer will only fuel the engine when it sees throttle position change. So you really shouldn't be adding fuel during braking. This would be contradictory.

 

Hey Lady, I see your point, and it does makes sense.

 

Maybe mine isn't working right, or my seat of pants experimentation is slightly skewed BUT I have experienced this. With the EB switch turned on, towing some weight and then taking off from dead stop, I can feel a power difference while in the same gear if I turn the EB switch OFF. The engine even sounds a bit different. Again, this is running up thru the gears not slowing down. I have noticed the same type of thing while running along, turn the switch on or off, you can hear a difference. Now I don't have a guage to actually see or verify my imperical testing but over a 1,300 trip using various EB modes I have come to the practice of leaving the EB switch off until I need the EB.
Agreed, it would make sense that you would "burn" more fuel with EB engaged while idling - you can hear the back pressure. Also when coming to a stop - back pressure keeping r.p.m.'s high as well as the weight of the truck pushing on the drivetrain. Back pressure is not diesel friendly.

 

GMSCOTT, I don't have an auto, so I can't speak on your truck.

I can say that mine is either on or off, and I can tell the difference, not only in sound but in feel. If my switch is left on during acceleration, the brake will pop on and off in between shifts (annoying).
The ecm makes sure it is not engaged when you are on the go pedal via the APPS.