40 mpg Prius vs 50 mpg European Diesel cars - Page 4

 

"A differential has one input and two outputs but lacks the variable
ratio capability."

It most certainly does have the variable ratio capability.  Spin the
driveshaft at a constant speed; you can vary the speed of the right
wheel by varying the speed of the left wheel (as happens when it loses
grip).  This is exactly what MG1 does to "vary" the "ratio" of the PSD.

 


Having driven a 1996 Honda Civic HX with the belt-cone CVT and 199K miles
on it, I have to say never going back to auto/manual, but NEVER going back
to a belt-cone CVT.  It started making funny sounds around 70K miles, and
has never been the same since.  It sometimes "slips" now as if the 1st or
2nd gear were missing teeth, besides the Honda techs saying there was a lot
of debris in the tranny fluid.

Yup, the PSD on the Prius is the way to go.

--
Joseph nugundam ===========/==\=IIGS=/==\=============/==\==============/==
\
#      FreeBSD: The Power to Serve      >> www.freebsd.org                  

 


It turns out that GM of all people is way ahead in devloping hybrid
diesel - in buses. the following links tell the story - diesel, hybrid,
regenerative braking - the lot! 60% gain in economy.

www.shadetreemechanic.com/allison_hybrid_drive.htm

www.gm.com/company/gmability/edu_k-12/9-12/fc_energy/hybrid_allison.html

www.hybrid-vehicles.net/gm-allison-hybrid-bus.htm

I owe it to an Australian electronics magazine - Silicon Chip - which
is running an article in its June issue on this GM - Allison project
which is not pie in the sky - the vehicles are operating in various
parts of the US.

 Scott wrote:

exellent post!

Also, don't forget the pollution aspects of diesel, even modern ones, vs
the low emissions Prius.

 
I understand that! I got a new work truck last October, a TDi that replaced
a gasser. In November I had to make an emergency trip to the far side of the
Big Rez in the middle of the night. I put over 400 miles on it before seeing
an open gas station - the old gasser had a range of 350 miles max. The new
TDi has a range of at least 600 miles with the same 30 gallon tank.


Depends on the service. I believe on the open road you are right - diesels
are wonderfully efficient for moving vehicles at highway speeds and
turbocharging with 1.5 bar allows more engine downsizing than hybridization
does at this stage of the technology. Around town hybrids (at least the
Toyota style) do much better than conventional diesel power trains by virtue
of partially overcoming many of the huge inefficiencies of using the same
engine for low speed movement as for cruising or for climbing hills at
highway speeds. A diesel hybrid would combine both advantages if the issues
of frequent start/shutdown cycles of the engine can be addressed.

A serial hybrid - where the engine just kept the battery in a proper state
of charge and the electrics actually turned the wheels - is the next major
step. In that application, a 1 to 1.5 liter turbocharged diesel would be
plenty of power for any sedan. We ain't seen nutthin' yet!

Mike