Toyota not working on diesel hybrid
2010 Toyota Prius - Click above for high-res image gallery
There's no doubt that the Toyota Prius is the most well-known green car in the world, a fact that's as often attributed to the car's distinctive styling as it is to the car's impressive fuel efficiency. The latest 2010 model pushes that efficiency to a new level with a combined 50 mpg rating here in the States. Up next is likely a plug-in version of the Prius, almost certainly with a lithium ion battery.
Of course, there are ways to improve the fuel efficiency of the Toyota Prius besides adding a plug. According to Toyota R&D head Tasatami Takimoto, though, the options that the company is investigating doesn't currently include a diesel powerplant. He says:
We already make a diesel hybrid truck in Japan, but in order to mass-market diesel hybrids we need to make the exhaust emissions much cleaner, and that requires development. You have to combine this clean emissions technology with the hybrid system cost, so that means that, currently, it's a very high-cost powertrain for us. So for Toyota, it will take many more years.
Gallery: Toyota Prius
[Source: Autocar]
Reader Comments (Page 1 of 1)
nrb 10:29AM (6/18/2009)
They probably don't want to put up with the rumors of them licensing their diesel technology from Ford.
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Mike Z 10:52AM (6/18/2009)
Also, AFAIK most diesel emission control systems seem to not work well with 'start-stop' engine cycles. Maybe HCCI would be a better mix.
Also, I believe from speaking to engineers that it's much harder to do the quick start-stop operations with a diesel engine anyway.
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L3 11:16AM (6/18/2009)
Oh, how journalism has changed.
Back when I was a cub, we reported on things that people did, not what they didn't do...
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downtoearth 11:25AM (6/18/2009)
I can't see the point of diesel hybrids applied to passanger cars.
Instead of paying for the ultrahigh fuel delivery system, direct injection, (twin)turbocharging, intercoolers, heavier and more expensive engine blocks and drivetrain components to sustain higher torques, particulate filters and NOx reductors, all of which have to be put into a modern diesel engine to make it competitive and meet emissions regulation, why don't we just invest this cash into a larger battery?
This will allow stroneger electric assist/longer all-electric distance. The simple and cost effective and rather durable Atkinson engine remains. The fantastically simple drivetrain (no clutches, no gearboxes) remains. And we are one step closer to an electric car with a range extender with mpg significantly beyond current ordinary hybrids (think 65-70 real life mpg for the Prius on 90% of miles covered).
Regarding this Toyota guy words, so far as I know Toyota has some diesel cleaning technology called D-CAT already deployed in Europe. It is a bit dirtier than Mercedes/BMW piss injection systems and on par with cleanest particulate filters only diesels. I also heard rumors D-CAT NOx reducing capability detoriates over time however. If these rumors are true, it makes sense why he says they need to develop it further.
Car (all diesels)/ point for pollution reduction:
BMW 330d BluePerformance (urea injection + particulate filter)...........46 out of 50
Mercedes E 300 Bluetec 7G-Tronic (urea injection + particulate filter) 46 out of 50
Mazda 6 Sport Kombi 2.0 CD (particulate filter only)............................ 45 out of 50
Toyota Avensis 2.0 D-CAT (particulate filter + D-CAT)........................ 45 out of 50
Alfa Romeo MiTo 1.6 JTD Multijet (particulate filter only)......................45 out of 50
Source: http://adac-ecotest.awardspace.biz/
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steve 11:28AM (6/18/2009)
These are all valid issues because they use a parallel Hybrid drive train ie. the ICE drives the wheels, and the electric motor assits or replaces it it some of the time.
If they went for a series hybrid like the volt, ie an electric motor that drives all the time, with a range extender ICE driving a generator. The only time the ICE runs is when the batteries need topping up, and it starts, runs at max power / max efficiency for a short period, then shuts down again.
As long as they continue to use the ICE as the primary drive, then their complaints about a diesel hybrid will continue to be true :(
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3PeaceSweet 2:42PM (6/18/2009)
A through the road hybrid with a small diesel in the front and larger electric motor driving the rear wheels should be fairly low cost. The savings from using the smaller diesel engine can pay for the battery and motor (hopefully).
Derk McRockgroin 4:07PM (6/18/2009)
Unlike Honda's IMA (Assist hybrid), with its 13 hp motor in the Insight, Toyota's 2010 Prius uses a more powerful 80 hp motor with 153 lb-ft of torque. Toyota's "Series Parallel" Hybrid Synergy Drive is adequate for most driving conditions under electric mode. All Toyota needs is a more powerful battery pack and an adjustment for the gear ratio.
A plug-in Prius can run like the Volt as you describe, (max power / max efficiency for a short period, then shut down.) But the Prius’ ICE has the advantage of a mechanical path to the wheels, thus reducing torque losses.
Creating a Diesel Synergy Drive would be more of a hassle than improving the battery of an existing power train.
jharlan 12:15PM (6/18/2009)
That type of strategic planning will help you catch up with Chrysler. Here come the Germans, here come the French!! Maybe even Ford will chunk off a little Toyota market share! It's what they deserve.
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jpm100 12:29PM (6/18/2009)
I thought their hybrid system wasn't suppose to cost a lot as the counter argument to those who suspected they (at least in the past) were dumping hybrids.
"You have to combine this clean emissions technology with the hybrid system cost,..."
Whoops.
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Snowdog 1:00PM (6/18/2009)
Define a lot. I don't think anyone claims it is less than say $2000. Say diesel is another $2000. You are doubling the markup but you will likely on see a small increse in fuel economy.
usbseawolf2000 4:33PM (6/18/2009)
A small, light, reliable and inexpensive Atkinson gasoline engine can achieve Diesel efficiency (37%) without high pressure fuel injector or after-treatment exhaust system.
The only advantage going for Diesel is the extra energy (~15%) in fuel. It comes down to extra energy you get in the fuel outweighing the Diesel hardware premium cost; assuming Diesel fuel cost the same as gasoline.
Diesel hardware premium is $4,755 (Jetta S vs TDI) and fuel price is $3 per gallon. TDI would save 45 cents due to the 15% extra energy. It would take 528,000 miles for TDI to pay for itself at 50 MPG. The assumption is that Jetta hybrid would also get 50 MPG like the Prius (although Prius is a bigger mid-size).
In summary, Diesel hardware premium cost can not justify the extra 15% MPG it will gain. Gasoline Atkinson cycle engine is more cost effective and cleaner choice to hybridize.
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Sam 5:36PM (6/18/2009)
The markup on the TDI isn't because of the TDI engine fully, but because the whole car is much more equiped than the jetta s. If the exact same spec car with a TDI vs Gasoline engine was compared the markup would be closer to 1500-2000 dollars. A better comparision would be the Jetta SE or SEL with the TDI, as they are more similarly equiped. The markup on the TDI with extra equipment isn't a dumb strategy for Vw. Since the TDI is in high demand people will pay extra for a car that is more equipped than they may necessarily need or want.
This strategy has also helped ford make more money in the last quarter as alot of their new offerings are comming more highly equiped and less stripper cars are being sold.
It's just a matter of smart marketing and profit making for the companies.
You also forgot to add the fact that the Jetta TDI keeps it's value in resale over a period of 5 years the TDI is worth nearly double that of what a gas version is worth. If you include that you get a completely different picture of how your saving.
usbseawolf2000 10:34PM (6/18/2009)
Misconception about Hybrid Synergy Drive is that people think it is a parallel hybrid like Honda's IMA system.
HSD has a power split device that continuously varies between parallel and series modes. You would think it will complicate mechanically but it is really very simple and elegant.
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usbseawolf2000 10:45PM (6/18/2009)
Sam,
Good point about the equipment level. Most people will compare a strip down gas version to TDI. Prius has been compared to a stripped down Corolla and Prius can pay for itself.
There is no evidence that modern Diesel will have high resale value, especially with high pressure fuel injector and complex exhaust system.
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Sam 2:42PM (6/21/2009)
Particulate filters are nothing new in europe where they have been used since 2004 in vehicles. While these haven't been completely problem free, the resale value of diesels hasn't changed much at all. The SCR systems vw uses as well as the Urea free exhaust aftertreatment used in the jetta shouldn't be any more troublesome than these systems.
Your statement should read, there is no evidence that Modern diesels will NOT have high resale value, as there is evidence that in the past they have.
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Sam 2:44PM (6/21/2009)
oh, and high pressure fuel injection systems have been used for many years. In fact Even the old diesels had high pressure injectors. The new common rail system is proving to be even more reliable than the old one. The fact that they're quieter and more powerful would only BOOST resale value. Not hurt it.
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