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Old 03-22-2005, 05:50 PM   #5
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Re: Re: Hybrids from an engineering standpoint

Originally Posted by CraigFL
1. Because you change the way the vehicle is powered(electric motor), you can now take advantage of regenerative braking which is "free" considering it was being thrown away as heat previously.
Quite true and it is completely wasted energy with plain old brakes. But, energy out can only be a function of energy in. Of course you start with fully charged batteries, but you can only make as much electricity as fuel you burn. You can recapture some of the energy you used to make you go when you stop, but the returns are much smaller. I see the benefits to all of the conservation techniques the hybrid uses, but in my little head I can't see how the extra energy changes can be offset by regenerative braking. I'm sure its possible, I just remember chemistry and all of the energy that gets lost in something like that.

2. You can run the internal combustion engine only when you need to and only where it's most efficient. If the IC Engine was the prime mover, you don't get that choice because you give the operator a throttle pedal and he/she decides. If you have a hybrid, the computer decides how the engine runs-- it is most efficient at wide open throttle and under higher loads.
I can definitely see the benefit of that... the computer can be programmed to make those decisions. I can safely assume that most of us aren't autistic savants who can read into a real-time 4D fuel map and decide when to do it on our own

Ok, here's another conundrum that comes to mind. You take a Prius and a Jetta TDI in Phoenix, AZ and drive them both to Flagstaff, AZ. Its about a 7000-ft climb in about 140 miles. After the trip, which one will get the better mileage, and will the Prius be able to recharge faster than it needs the power to maintain highway speed? And... if the Prius lags behind, is this an indicator of the hybrid's long term feasibility, or just a kink that needs to be worked out?

I used this comparison since they have similar outputs, similar weights, and other things in common, except the diesel is the current paradigm of simplicity while the hybrid is expectedly complex.

It makes a crystal clear choice for me if I were buying in this segment, which makes me think that hybrids are in part a marketing ploy. Just a thought.
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