Don Wells wrote:Yes, there is some regeneration going on in "B" in my Prius. But I also hear a sound from the engine similar to a conventional ICE braking against compression (compressing air without burning fuel). That's one of the fuel injection strategies in my Ranger, and I'm pretty certain that just about any modern fuel-injected system functions in a like manner. As long as engine rpms are above 2 000 and there is no voltage from the throttle position sensor, the injectors don't pulse and the engine is effectively functioning as a dynamic brake. I use this technique all the time when driving downhill in my truck, but in the Camry, the transaxle is continuously variable, so I don't get to select a gear and I can't really tell what it's doing. Getting maximum economy out of this car will require a different mind set! I wish that Toyota would be more precise in their explanations of their hybrid drive technology. "B" is one of the most obscure features. Our salesman didn't even know what it was! I figured it was for dynamic braking and checked the display to make sure. The owner's manual warns against doing this for "extended distances", whatever THAT means . . . (I suppose I should't go down the Siquiyou Pass or the Coquihalla Canyon in "B"!) Toyota seems to be hedging a lot with their hybrids, and I'm really disappointed that they're so adamantly opposed to a plug in option. I am a real-time software designer, so I can guess what some of their techniques might be. First, the software probably commands the small motor-generator to spin the ICE up to matching speed without any fuel injection, and the spinup is probably profiled to minimize jerk. Second, they probably start fuel injection with a minimal amount, and gradually ramp up the injector pulse width (amount of fuel) over several revolutions of the ICE. Activation of the ICE in my 2003 Prius is generally very smooth, and I usually don't even notice it. This is good engineering. The Toyota Hybrid Drive is about as much software as it is hardware. I think that my 2003 Prius is effectively bug-free, and I stand in awe of that engineering accomplishment! We've been driving GM cars for so long, the Toyota feels like it was made on a different planet! I've had serious complaints about the engineering that went into my sweetheart's car, especially with respect to the poor quality of its expensive, front end wheel bearings and its VERY undersized brakes. When I first touched the brake pedal on the Camry, I thought I was going to activate the airbags! The whole car has an overall superior quality when compared to the vehicles we've been driving. (My truck is basically a Mazda with a Ford engine, and while it's far more reliable than the Cavalier, the Ranger is STILL a truck and it's designed for work, not comfort.) I'm very impressed with the Camry. We're supposed to take delivery some time this week, and having never owned a new car before, it's a little exciting. robert luis rabello "The Edge of Justice" Adventure for Your Mind http://www.newadventure.ca Ranger Supercharger Project Page http://www.members.shaw.ca/rabello/ |
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