why no prius diesel hybrid?!

[usbseawolf2000]

Originally Posted by Flying White Dutchman

if you remove the expensive Diesel emission equipment then you have a dirty diesel again and hybrid wil make no sense

The key is to find synergy between Diesel and electric motor. For gas electric, we saw how Atkinson cycle ICE synergized with electric motor.

For Diesel, the key is to find a low emission diesel combustion cycle that produces very low emission. If the drawback of that cycle is low torque then bingo, we have synergy -- electric motor can cover plenty of torque. I just did a quick search and found this patent and this new concept for examples of low emission Diesel combustions. Toyota may be working on something even better, who knows.... low pressure combustion (if clean) can synergize too because this Diesel engine can be lighter and cheaper to produce -- narrowing the gap between gas and Diesel engines.

We know Toyota is working on a Diesel hybrid because it is one of the solution on their Ultimate eco-car.


We don't know how far they are in development of reaching Diesel-electric synergy and commercially viable it is. One thing for sure is that cost reduction in gas-electric is also step forward for Diesel-electric.

[DeadPhish]

I'm going to go out on a limb and predict that we WILL see a diesel hybrid fairly soon ( w/in 5 yrs ).....but it will be in a truck.

Why? Gasser hybrids are well accepted now and actually well proven technically. Now that that barrier is overcome it's a matter of squeezing the most out of the gasser motor with new technologies and to improve the synergy between ICE and e-motor with better battery technology. There is a lot of room for growth there. In addition in NA there is a HUGE HUGE market for midsized and small vehicles that can accept gasser hybrid technology. 75% of Toyota's current lineup could benefit by being a hybrid tomorrow.

Secondly, Toyota has a HUGE investment currently sitting idle. With Toyota's financial strength it's not a crisis situation by any means, but it is uncomfortable to have $1.2 Billion sitting idle with ??? prospects. This investment and this segment would benefit immensely by the introduction of some radical new technology that would improve fuel economy from the high teens to the high 20's mpg. Imagine a Tundra 5.7L that averaged 25-28 mpg day in and day out.

[spwolf]

Toyota already sells Diesel Hybrids in Japan, in commercial vans (like Ford Econoline or whatever that was called)... i think it came out in 2002 or 2003 and lineup has expanded to several trucks as well.

[miscrms]

I can see where you are going, and it kind of makes sense. I can see one problem though. At this point engine sizing for passenger cars is pretty much determined by 0-60 time and passing power. These are both areas where a hybrid assist can help, so you can down size the engine without giving up performance. On commercial vehicles engine sizing is based much more on load and gradability. IE how much can you haul, and how big a hill can you get it over? There is generally a lot less surplus power compared to personal vehicles. This doesn't seem like an obvious fit for hybrid assist. I suppose local delivery vehicles would be an exception, ones that do a lot of stops and starts.

Not really sure about all that, just thinking out loud.

Rob

[spwolf]

Originally Posted by miscrms

I can see where you are going, and it kind of makes sense. I can see one problem though. At this point engine sizing for passenger cars is pretty much determined by 0-60 time and passing power. These are both areas where a hybrid assist can help, so you can down size the engine without giving up performance. On commercial vehicles engine sizing is based much more on load and gradability. IE how much can you haul, and how big a hill can you get it over? There is generally a lot less surplus power compared to personal vehicles. This doesn't seem like an obvious fit for hybrid assist. I suppose local delivery vehicles would be an exception, ones that do a lot of stops and starts.

Not really sure about all that, just thinking out loud.

Rob

yes, pretty much that + plus with delivery vehicles, you dont worry about refinement, all you care is saving the gas...