Toyota expands auxiliary electrification on new Lexus HS250h
2010 Lexus HS 250h – Click above for high-res image gallery
With the introduction of the new HS250h, Lexus brings forth the first dedicated luxury hybrid. In the process it's also expanding the electrification of ancillary components. Ever since the original Prius, hybrid engineers have been replacing mechanically driven systems with electrically driven equivalents. For example, components like hydraulic power steering pumps are replaced by electric versions, as are air conditioning systems. This is partly to ensure that these systems continue to function when the engine has been shut off and electric drive is active.
These electric systems are also more efficient and can be controlled to provide their functions on demand, thus reducing parasitic losses from driving them continuously. The latest addition to this electrified drive lineup is the transmission oil pump on the HS250h. The oil now also flows over the electric drive motor, improving its efficiency. The new electric pump is actually the second on Toyota's new for 2010 hybrids. The new Prius and HS250h both feature electric water pumps as well.
Gallery: First Drive: Lexus HS 250h
[Source: Green Car Congress]
Photos copyright ©2009 Drew Phillips / Weblogs, Inc.
Reader Comments (Page 1 of 1)
Sean 5:05PM (5/31/2009)
I was just thinking about this on my Gen2 Prius...if the water pump was electric too, the engine wouldn't have to come on when it's simply too hot just to drive the water pump. (Seems counter-intuitive, doesn't it. I'm surprised they didn't do this in Gen2 when they were already adding electric A/C.)
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MikeInNC 8:27AM (6/01/2009)
Corolla Hybrid.
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KIB2 10:05AM (6/01/2009)
That is crazy ugly, it looks like the last generation honda civic. http://www.youtube.com/watch?v=vEY5wycJtIE
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Gary 3:32PM (6/01/2009)
It seems scary when you start to have more systems run off an electric pump which is more prone to failure than a mechanical one. AC and power-assist steering is one thing, but it doesn't lead to catastrophic and expensive powertrain failure.
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frankbank 8:58PM (6/01/2009)
Toyota is second with this one. GM's 2 Mode system uses an electric trans oil pump, and used oil to flow on the motor to make them more efficient. It began production two years ago.
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