If any vorticians will be car shopping this year, let me save you some time ..
I did some test drives recently and then online analysis - of the Prius, and its competitors. Since the Prius still sells at a premium price - it would be nice if there was a viable option in a hybrid vehicle that could be a good substitute at a lower price - but I came to the conclusion that the Prius really has no competitor for now. And the reason for this will probably be a great surprise to you. I thought the Honda Insight might be close, but by comparison it is a "lawn-mower" in power, and with similar but not better gas mileage. But it is the closest competitor that there is for now. Honda should have bitten the bullet and gone with a license from Toyota, instead of its over-hyped CVT or continuously variable transmission - which is supposed to provide infinite ratios to keep the engine operating within its most efficient range. But the Insight's smaller engine and lighter, smaller size still gives performance that is a joke compared to the Prius. You really need to drive both on the same day to realize how much difference there is. This is not an viral ad by a fan-boy. It is the simple truth that the Prius is a vastly superior mechanical design, even despite its inferior batteries, and even despite what is only an average gasoline engine - and it is pretty ugly to my thinking - but now a surprising answer emerges as to why the car is superior, and has been for years. The non-secret to the Prius, as it turns out, is the non-word PSD. It is not glitzy and in fact is almost hidden from open discussion on newsgroups. It is a new wrinkle to an old transmission that was made popular by Henry Ford, but goes back even further. Side note: with its vastly superior diesel engine, the VW Jetta TDI could be a future Prius-killer if only they would license the PSD from Toyota. Or maybe Toyota will put a diesel in the Prius next year. Who knows? The open secret is the Prius transmission, and it is called a "Power Split Device" (PSD). It is an "epicyclic" or "planetary" gear, similar to those used in many automatic transmissions. OK that is a yawner so far, and means very little, but the new twist is having two distinct inputs - one is the ICE, which works at a near constant speed and the second is the electric motor which permits the low end torque that can allow the near constant speed. In this case, one plus one equals four. It sounds so simple but the fact that it is non-obvious to experts, must be relevant. Yet I am convinced after close analysis, as are many others, that the PSD is the only real Toyota "secret" and the key to its vast superiority . but it is in plain view - so why haven't others jumped on it? Has this story appeared in print before? . like Popular Mechanics. I could have missed it. Maybe even auto engineers just don't get it yet. Admittedly the epicyclic concept is difficult to explain, and without animation it is hopeless, and the double input epicyclic borders on 'real magic' IMHO. There is an attempt here, but it is not a great explication. I hope someone will put up a better site. http://prius.ecrostech.com/original/Understanding/PowerSplitDevice.htm Jones
