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Honda Civic, Hybrid Cars
#15 of 34 Re: A few points [ny1911]
Mar 31, 2006 (9:36 pm)
" The Prius easily has the more sophisticated and clever drivetrain."
Can you explain this to me?
#16 of 34 Re: A few points [rysa4]
Apr 01, 2006 (4:15 am)
March 2006 Motor Trend magazine compares the Civic and Accord Hybrids to the similar cars (Prius and ?) from Toyota. They concluded Toyota's hybrid system was better than Honda's system in early 2006. Good luck with your research. I bought a Civic LX and not a Hybrid on 3/27/06.
#17 of 34 Re: A few points [rysa4]
Apr 01, 2006 (4:48 am)
The Prius is really cool. It uses 2 electric motors, a planetary gear set and the internal combustion engine. The larger traction assist electric motor gets the vehicle moving and the smaller motor "starts" the engine once it gets up to speed. But it does so not by cranking the engine to a start, rather it locks one of the components of the planetary gear set forcing the engine to be coupled to the wheels (and kick over)...kind of like push starting a manual transmission.
The prius was designed as a hybrid, and it has a more powerful electric motor. The civic is a basic parallel configuration, which works well, but is an adaptation of an existing platform. HAving said all of this, I don't know which one I would select. It really would come down to driveability, and I haven't driven the newest versions of either car.
#18 of 34 Re: A few points [ny1911]
Apr 01, 2006 (4:59 am)
> the smaller motor "starts" the engine once it gets up to speed. But it does so not by cranking the engine to a start, rather it locks one of the components of the planetary gear set forcing the engine to be coupled to the wheels (and kick over)...kind of like push starting a manual transmission.
I would absolutely love to find out where you heard that. Do you remember?
That isn't even remotely correct, and it's very easy to disprove too. Just try explaining how the engine is started while in reverse... which happens to me every single morning I pull out of the garage. That's too slow and the opposite direction.
Anywho, the way the engine actually starts is the smaller of the two motors spins it all the way up to idle speed, waits for oil pressure to be established, then injects fuel and sparks.
#19 of 34 Re: A few points [ny1911]
Apr 01, 2006 (6:58 am)
Thank you for your response. I can see your point. My only comment is that the HCH actually gets close to or at its EPA estimate for mileage while the Prius usually isnt even close to its EPA estimate.
Of course that number is based on testing procedure which perhaps represents the engines comparatively moreso than the electric motors.
At this point, I dont own either car FYI.
#20 of 34 Re: A few points [john1701a]
Apr 01, 2006 (9:38 pm)
I remember from our customer's dismantling of a prius. They are a tier I supplier. But there are now descriptions online: http://auto.howstuffworks.com/hybrid-car6.htm
Maybe you aren't considering the flexibility afforded by the planetary gear set?
#22 of 34 Re: A few points [ny1911]
Apr 02, 2006 (5:33 am)
Oh! Now I know where your misunderstanding originated from. Having worked with the PSD for so many years, it never would have dawned on me that the description of tolerance could get interpreted that way.
That particular engine activity is just the by-product of RPM exceeding a maximum, not the usual startup process. And just because the engine is in motion at speeds above 42 MPH, does not mean it is actually using any fuel.
#23 of 34 Re: A few points [john1701a]
Apr 03, 2006 (10:18 am)
"And just because the engine is in motion at speeds above 42 MPH, does not mean it is actually using any fuel. "
John, are you referring to the ICE? If it is not using fuel, but is turning, that would mean it is dragging down MPG, right? Otherwise how can an ICE be in motion without consuming fuel?
Apr 03, 2006 (12:20 pm)
If it is turning but not using gas, then it is braking the vehicle. How severe that is depends on the compression and friction of the engine. But this is nothing new. In my old '87 VW, when I took my foot off of the accelerator, the fuel would cut off. I still consider such an engine to be "running" though
In order for the vehicle to stay moving without the engine using fuel, it must either be coasting or be driven by the electric motor...which would be an inefficient design. With the Prius, if the engine is not running (or being started,) it should not be spinning.