So you want a diesel hybrid...

[WannaWagon]

Stumbled on this interesting article:

http://www.evworld.com/view.cfm?section=article&storyid=807

The author argues that diesel-hybrid vehicles are not feasible, apparently because the benefits don't significantly outweigh what you can already get from gas hybrids. I think his argument is flawed because he bases his case on the Benz E-class platform, a heavy beast. He also doesn't consider the benefits of operating a diesel hybrid on biodiesel. I think a smaller, lighter diesel hybrid that's more affordable to average folks (i.e. in line with the Toyota Prius) would be a hit.

[83-240D]

isn't honda working on a stratified charge diesel engine? cupped pistons, 15-1 compression or higher, something like that?

[Joe Blowe]

The author argues that diesel-hybrid vehicles are not feasible, apparently because the benefits don't significantly outweigh what you can already get from gas hybrids.

Cost benefit arguments of diesel-hybrids v. gas-hybrids aside, most articles I've seen on diesel-hybrids state that they only achieve a usual 25% increase in fuel economy over today's diesel engines. With the increased price tag of diesel-hybrid car, the breakeven period would be even longer over a gasoline car. His argument is not all together flawed.

I think a smaller, lighter diesel hybrid that's more affordable to average folks (i.e. in line with the Toyota Prius) would be a hit.

Coming soon from Honda (wink-wink, nudge-nudge)...

[83-240D]

http://www.ai-online.com/issues/article_detail.asp?id=582

[Rick Miley]

A diesel/electric hybrid is already in the works by Mercedes-Benz. To see more, you have to go to here. Click on "The Vehicle" at the bottom, then "The Veil is Off" under January 2004, and finally "Performance". It combines a 247 hp V8 diesel with a 67 hp electric motor. Note that this info is over a year old.

[phidauex]

The mileage benefit from gas hybrids is not that great either... The GMC Sierra hybrid only gets 2 MPG more than its regular counterpart (and the same mileage on the highway). The benefit there is emissions, which are 60% less.

Diesel engines run great in a constant RPM, constant load situation, which makes them a good candidate for hybrid drivetrains.

Which is why Dodge is releasing to its fleet market the Ram 3500 in a diesel hybrid, and the Sprinter in a diesel hybrid (available next year, drool). Incidentally, the Sprinter will have a 'plug-in hybrid' configuration as well, so it can be plugged in and driven on pure electric power around town, only using its engine when it needs to exceed that time or distance.

The author talks a lot about diesel hybrids not being effective, but then he just wanders off in a different direction and explores the interesting (but irrelevant, in this case) idea of a powerful MB gas hybrid. Great idea, but he still does not explore why a diesel engine would not make sense in such a configuration, with its already lower emissions and greater efficiency.

And of course, as you've all become accustomed to hearing me say, it ignores the biodiesel issue entirely (which in his France discussion is key, because of the French gov't's commitment to biodiesel).

I do appreciate the author's excitement about powerful hybrids. I've always been a proponent of the idea that having electric motor support to your drivetrain could make for fast powerful cars that are still more efficient than regular cars. The idea of the tiny, dangerous, slow, cardboard hippy-car as being the only path environmental friendliness can take is flawed, and this guy has some big ideas on how to make cars better in every way through a hybrid system. But his blatant tossing out of the diesel concept is a bit strange to me.

peace,
sam

[turbodiesel]

I just read an article that MB is coming out with a hybrid S400 CDI, don't know if it will be available in the USA, though.

[WannaWagon]

Originally Posted by phidauex

The mileage benefit from gas hybrids is not that great either... The GMC Sierra hybrid only gets 2 MPG more than its regular counterpart (and the same mileage on the highway).

While I support your other comments, this one begs a response. The GMC Sierra is a poor example of the hybrid phenomenon. It is what they call a "mild hybrid," and in this case that means that the battery/electric motor do not assist the vehicle's forward motion. Instead, they exist as a kind of on-board generator to power tools, an electric grille, and other nonsense. The only "hybrid" aspect of this truck, really, is an idle-stop feature that shuts the gas engine off when you're waiting at a stoplight. In my opinion, just another half-effort from old GM.

My 2001 Honda Insight gets 55 mpg in almost all driving conditions (and more on the highway), so I can tell you there are huge mpg benefits from "real" hybrids.

[phidauex]

No, you're right, the Sierra is a poor example of a hybrid. Too little too late, as usual from GM.

My comment was directed toward the 'only 25% increase in mileage from diesel hybrids' comment. Even the Prius only gets about 20% better mileage than the Echo, the closest configured Toyota. Of course, the Prius also has all the enhancements like tires, weight reductions, exhaust treatments and all the other things that aren't related to the hybrid drivetrain.

The Insight was designed with mileage in mind, not emissions (like the Prius) and there really isn't any other car that is similarly configured, so its not as easy to compare, but it might be exceeding the 25% better mileage than its non-existant non-hybrid counterpart. However, if a 'regular car' can get a 25% increase in mileage through the use of a strong hybrid drivetrain, then that actually compares quite favorably to existing gas hybrids, and I don't see why 'only 25%' is a bad thing.

Anyway, not knocking gas hybrids, just trying to defend my comment. However, GMC rarely makes a good example of anything.

peace,
sam

[leejxxxxx]

Originally Posted by phidauex

Diesel engines run great in a constant RPM, constant load situation, which makes them a good candidate for hybrid drivetrains.
sam

I'm surprised they don't have a diesel electric combo like a locomotive. A constant speed diesel runs at its most efficient speed driving a generator which supplies power to run an electric motor which moves the vehicle.

[Triffin]

"I'm surprised they don't have a diesel electric combo like a locomotive. A constant speed diesel runs at its most efficient speed driving a generator which supplies power to run an electric motor which moves the vehicle."

I thought of this too .. I think the reason it
isn't done is that you end up with fewer mpg
when the diesel engine is used to run a generator
vs running the drive train .. anyone know for
sure ??

Triff ..

[rg2098]

Originally Posted by leejxxxxx

I'm surprised they don't have a diesel electric combo like a locomotive. A constant speed diesel runs at its most efficient speed driving a generator which supplies power to run an electric motor which moves the vehicle.

This idea with a small electric motor at each wheel would be interesting with modern computerized traction controls. Plus I would route the power from the generator into an inverter to use as a standalone powerful generator for power outages and such.

[aklim]

The "Type R" thing looks like a minivan. Will it be FWD or RWD? Also I have driven a couple of hybrids and not been impressed. Lackus Accelerationus was their main problem besides the fact that they are FWD and I don't pay more than $10 for a FWD car.

Edit: Found some stuff that said it was four wheel drive.

[Ara T.]

He seems to think that diesels put out more carbon dioxide than gasoline engines. As far as I know diesels don't contribute as much to global warming.

[Triffin]

I'll take one of these please

http://www.gm.com/company/gmability/adv_tech/100_news/astra_011005.html

Triff ..