still so sad...

zenMachine · Oct 31, 2007

Mr Toyoda himself visited the Grand Opening of a new Toyota dealership near us when we were shopping for our new car last February.

We missed him by a few hours, but the sales lady told us that the local guys had taken him on a tour
of the surrounding areas (i.e. farms and urban cowboys) and explained to him why the Tundra was the perfect
vehicle for this type of market. I suppose he couldn't agree more, as Toyota was getting ready to unleash that monster truck upon middle America.

Point being, they should also have taken him to a typical after school athletic event (soccer, baseball,
what have you) and let him see for himself how many Odysseys there are in the parking lot compared to Siennas.

Anyhow, we test drove the Highlander Hybrid that day and thoroughly hated it.
The Prius was just an afterthought that somehow got stuck, and I'm still grinning...

patsparks · Nov 1, 2007

Thanks Daniel for expanding on my observation. A great job.
<div class='quotetop'>QUOTE(daniel @ Oct 31 2007, 11:24 PM) [snapback]532872[/snapback]</div>

It's more complicated than that. 60% of the torque going to the PSD goes to the wheels, and 40% of the torque goes to MG1, which generates electricity, which can be sent to the battery or to MG2 to help drive the wheels.

Torque is the rotational version of force, and no power is delivered by applying force unless the thing being pushed on moves.

Thus, when the car is at rest and you step hard on the accelerator, the engine revs up, turning the associated part of the PSD (I think it's the planet carrier, but I always get that confused) but until the car gets moving, none of the torque applied to the wheels does any work, so ALL the power goes to MG1. As the car accelerates, progressively more of the power goes directly to the wheels, and less to MG1.

Therefore, at low speeds more power goes through the electrical path (engine to PSD to MG1 to MG2 to wheels) and at freeway speeds more power goes through the mechanical path (engine to PSD to MG2 and wheels).

This is an elegant solution to the fact that at low speeds the electrical path is more efficient, while at freeway speeds the mechanical path is more efficient.

On the other hand, a series hybrid lends itself better to be a PHEV, since the Prius MUST turn the engine above 42 mph, and lacks sufficient acceleration to keep up with traffic from a stop light unless it burns gas. A series hybrid will have a big enough electric motor (or four) to operate entirely on electric while the batteries hold out. The Prius will be the better choice if you drive very long distances a lot, since it will be more efficient while burning gas than a series hybrid that's burning gas. But the series hybrid will be the better choice if you mostly drive within its electric range and can avoid burning gas at all; while having the ability to burn gas when it's necessary to make a longer trip.
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Click to expand...

ShellyT thanks for that, I see what you mean but unfortunately GM will put the series hybrid in a giant size car I don't want to drive although I can see it may appeal to the American motorist's (bigger is better) tastes.
If it comes in a medium size package with a no petrol range exceeding 100km then a plug in series hybrid could be what I need. Seems the series hybrid will be hard to make light as it needs an electric motor big enough to provide 100% of the power at peak demand plus a battery plus an internal combustion engine to lug around. Then it needs a chassis strong enough to carry the whole lot.

still so sad...

zenMachine Just another Onionhead

patsparks An Aussie perspective

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still so sad...

zenMachine Just another Onionhead

patsparks An Aussie perspective