Ian, I wish you would apply this amount of scrutiny to the generator. Even with the modified
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Originally Posted by IamIan
[a whole lot, some of which was relevant]
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The pusher has higher peak, and across a large rpm band it is a matter of load management (in both cars) to keep the ICE efficient.
If you are stop n go, or hiway cruising, the pusher can select an appropriate gear and load up while using the ICE (with regen if that makes sense). Some of my best mpg in a stick is around town.
I don't know that there is a situation where your assertion is true. There are limitations to transmissions, but they are pretty well understood, your solution is smoke and mirrors, you don't have a reference design to base your position off of or relayed what situations it is optimized for.
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Originally Posted by IamIan
I'm saying the situation will determine which one ... the pusher ... or the generator ... is able to net better efficiency levels.
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no, the design of the pusher/generator in combination with the situation in combination with the ability of the system to let the driver react to changes in the situation will determine how efficient the system is. And an EV with a big battery and motor is part of both systems.
Quote:
Originally Posted by IamIan
The Pusher has a higher Peak Efficiency for part of it's BSFC operating range... If the situation allows the pusher to stay in that range ... than the pusher is more efficient.
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And if it doesn't the driver will do something different, period. The driver is in a sitiation, but also has influence on that situation.
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Originally Posted by IamIan
If the situation forces the Pusher ICE into the part of it's operation that the Generator is more efficient ... than the generator is more efficient.
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Lets say we drop to the peak generator bsfc line, in this imaginary system, the average load on the generator is going to be about the same, and it is going to drop down as well (or if it is a common situation the pusher is going to have an appropriate gear ratio for it). If output exceeds demand then you take another hit in charging/discharging the battery.
Quote:
Originally Posted by IamIan
Which one is net more efficient will depend on the situation
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No, that is one factor. We can nail down the situations and the designs better if you like, but you have to own your hypothetical generator design and let it stand up to scrutiny. It is obvious to me that the pusher should not be operated inefficiently, kinda like "doc, it hurts when I go like this. Well don't go like that!"
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Originally Posted by NeilBlanchard
The thing about a generator that makes it possible to have higher overall efficiency, is that the load on the engine is constant
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And you can keep the load within a few points of peak bsfc with parallel at greater efficiency, across a wide rpm range.
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Originally Posted by NeilBlanchard
, and since it has the battery as a buffer (and the peak torque can be met by the electric motor), it only needs to meet a bit more than the average energy used
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What prevents a parallel from using the the EV system as regen/assist + mass?
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Originally Posted by NeilBlanchard
, so the engine can be smaller displacement.
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the "buffer" comes at a cost too. But either one can use it. If it is less efficient though at all modes of operation, then you will need a larger ICE.
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Originally Posted by NeilBlanchard
Electricity is pure energy and doesn't need to be converted to heat to be used.
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All hail electricity.
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Originally Posted by NeilBlanchard
And with a large enough battery - and with a low drag car - and with the electricity coming from renewable sources, it can be FAR cleaner than any fossil fuel vehicle.
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this is not apples to apples though.
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Originally Posted by NeilBlanchard
245MPGe.
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mpge is a crappy way to compare fuel and electric. It just muddies the waters even more.
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Originally Posted by Occasionally6
Perhaps we should. While cost effective for DIY, where the front half of a car may be available at a reasonable price, at a manufacturing level any add on device would probably have a prohibitive price tag.
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I think we should consider that a small generator sized ICE in a pusher, with a synchronous motorcycle transmission, chained to a wheel, and that fits in a standard square hitch, is not going to be terribly expensive. I looked at just the proposed "efficient" controller and it was like $6000.
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Originally Posted by rmay635703
My case is an actual case
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Can you clarify, are you combining electric miles w/gen miles? And is your top speed like 30mph?