AutoblogGreen

Yes, diesels are better in than most hybrids. They MAY even be better than some PHEVs (Plug-In Hybrid Vehicles).

HOWEVER, diesels are NOT nearly as good as good as E-REVs (Extended-Range Electric Vehicles) or BEVs (Battery Electric Vehicles) which can 40 miles or more between charging opportunities.

Apparently, Audi is afraid of the plug.

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Agreed.

But at least it's possible for a typical person to buy a useful, affordable diesel today.

Meanwhile, I'm still looking forward to my affordable, family-friendly EV. Looks like I've still got some waiting to do...

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Current BEVs and PHEVs are jokes. The batteries are still too expensive to produce.

The Volt is a rebodied $15,000 Chevy Cobalt that will sell for $30,000. The Tesla is a $90,000 car that can't drive more than 250 miles in one day.

Audi isn't afraid of plugs. Audi is afraid of building cars that almost no one will buy.

It is good that auto companies are working on technologies that will address peak oil/global warming/energy dependence issues. But the time for those technologies to take a dominant position hasn't quite arrived yet.

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Tim sure must have lots of insider info on the auto industry to make broad blanket statements like that (or maybe it's just hot air without anything to back it up).

What's better than what depends a lot on the type of vehicle, manufacturer, driving style, fuel cost, etc. etc.

Audi is known for diesels, so it's really no surprise that they would say diesel are more important than hybrids. Duh. All car companies tend to proclaim their technology is best.

There is no magic bullet - we need all kinds of new technology solutions (arguing amongst ourselves about what's "best" won't do much good). Besides, you can make a diesel hybrid, or a diesel E-REV, so those technologies are not exclusive anyway. They can be complementary.

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'We will next year offer a solution, in all states of the USA, the high environmental requirements.'

Fantastic! So we'll see Diesels that aren't in the highest pollution bin possible (tier 2, bin 5) in CARB areas! Great, maybe now Diesel can be as green as a hybrid.

Oh, no wait, my mistake going off half cocked there. He probably just meant they'll meet the "tough" tier 2 bin 5 standards, which means diesels will be throwing off 3x the trace emissions of even an Accord v6 and more CO2 than a hybrid.

Spin spin spin.

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Speaking only of CO2, the emissions from a Prius are about 90g/km, and the BMW 123d 2.0L engine are about 140g/km. Not bad, considering the 123d is enormously more powerful, gets pretty great economy, and is available (in Europe only, still, boooo) as a coupé, a hot hatch and as a 5-door. The VW polo is down to about 103 g/km.

Hybrid Lexuses are close to the 200 g/km mark. Hybrid or diesel is at best only half of the argument. The size of the vehicle is more important than the technology, really. Vehicles like the Q7 are wasteful, even if they run on solar energy because they're so ridiculously large for no reason.

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Theoretically, a diesel/electric hybrid can be better than diesel alone, because a diesel that runs at constant load and RPM can be made more efficient than one that has to handle a wide range of loads and RPM.

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A hybrid powertrain is $3500 more than a gasoline powertrain. A diesel that meets bin 5 is $2000 more than a gas engine. A diesel hybrid would be $5500 more than a gasoline powertrain.

$5500 will buy a whole lot of gasoline.

Face it, a diesel hybrid does not make economic sense.

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"diesels will be throwing off 3x the trace emissions of even an Accord v6 and more CO2 than a hybrid."

I don't care I am going to buy a diesel car anyway.

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To Jared :

If we accept your data - it means that if Toyota brings us a surprize like Prius Diesel - it will cost in the US 24K instead of 22K.

If we assume that Prius gets 51 MPG (4.5 liter/100 km) - its diesel version must get 78 MPG ( 3 liter/100 km ). My calculations are based on comparison between VW Jetta ( Rabbit ) petrol vs. diesel.

100K miles = 160,000 km = 2400 liter ( 635 gallons ) of fuel saved. Even in the US with its relatively low fuel prices the difference is recovered in reasonable time.

And the diesel fuel in Europe is cheaper than the petrol one !

The diesel version of Prius will be the best option for taxi drivers and all those who dribe more than 50K km a year.

The best feature of the hybrid technology is that it doesn't contradict any other one. Hybrid is good, diesel hybrid is better , and Skoda Superb diesel hybrid running on B100 will be the winner!

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"The best feature of the hybrid technology is that it doesn't contradict any other one."

"If we assume that Prius gets 51 MPG (4.5 liter/100 km) - its diesel version must get 78 MPG ( 3 liter/100 km ). My calculations are based on comparison between VW Jetta ( Rabbit ) petrol vs. diesel."


Not quite.

One of the major inefficiencies of gasoline engines is throttling losses.

In a series hybrid, throttling losses can be eliminated completely.

In a parallel hybrid, throttling losses can be decreased substantially because a smaller engine is used (which operates closer to WOT) and it is not idled at stops.

Diesel engines do not suffer from throttling losses. Therefore, a diesel hybrid system is redundant in eliminating throttling losses. The advantage is not cumulative vs. a gasoline drivetrain.

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PS-

The Prius uses an Atkinson cycle engine, not an Otto (like in a Rabbit or most any other gasoline powered car) cycle engine.

The Atkinson cycle engine is more efficient than Otto, but has weak starting torque. The hybrid system makes up for the lack of lowend torque, thus allowing the use of the more efficient engine.

That is another reason why the affects of hybrid and diesel are not additive/cumulative.

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Dave, thanks a lot, Unfortunately I understand a little in mechanics, and you helped me a lot.

What about this car ?
http://www.autobloggreen.com/2007/06/12/diesel-plus-hybrid-equals-70-mpg/

Let's omit the "+" from "70+" inside the article. Even 68.5 MPG means 3.4 liter/100 km .

The gap of 1.1 liter per 100 km means 2200 liter per 200,000 km. Still it is a fair deal for taxi drivers. And of course the usage of B100 will make this cat almost perfect.

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Emil-

You don't seem to understand imperial gallons vs. US gallons. I reccommend you look it up.

The article actually directly compares the Prius (54.7 mpg US) vs. the Peugeot diesel hybrid (58.3 mpg US).

You see that the Peugeot is only expected to get 3.6 mpg (6.5%) better than the Prius. Nowhere near the 27 mpg spread you had hoped for.

"The Peugeot diesel hybrid should average better than 70mpg (58.3mpg US), which would mean its emissions levels would be lower than most other cars except for pure electric vehicles. By comparison, the Prius rates 65.7mpg (54.7mpg US). However, most motoring mags have found its real-world fuel economy ratings to be much lower."

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Dear Dave,
Thanks a lot for the info.
I accept your data, but it seems, that diesel hybrid doesn't have a significant advantage over the petrol one.
And we must keep in mind, that this model of Peugeot will be available "by the end of the decade". By the same time the next model of Prius will be available.
Also we can't compare the conventional diesel with the hybrid : diesels are better on highways, hybrids - in start-stop traffic.

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Honda should be commended for their efforts with the FCX, which is a quick view into the only reasonable choice (Hydrogen) for a future of automotive fuels. The problem of motor fuels and their environmental impact is far far more complex than what can be related in a short blog posting, but what we do understand (I've spent the last 40+ years working at the viability of alternative motor fuels) is that gasoline MUST be replaced in North America.

It might surprise many to know that in the United States alone, we use an average of 375 million gallons of gasoline a day, every day, all year long (that's 32 Super Tankers full of crude) in our 231 million gasoline powered vehicle fleet (passenger cars, light trucks, and vans).

Replacing those vehicles will take years, probably even decades, before alternate fueled vehicles will begin having any significant effect on the environment and our pocketbooks. Because of the time it is going to take, we need to make the right choices now and frankly the only known viable alternative (other than gasoline) is Hydrogen.

The best fuel of choice, as the bridge between now and when in our future Hydrogen will have a significant impact, diesel is easily the best choice. It (diesel) can be produced in volume, diesel has between 23% and 29% more energy (BTUs) by volume than gasoline, the fore and after technology for controlling emissions (NOx, HC, CO, CO2, and PM) already exists, and the infrastructure for delivery to the end-user is already in place.

Before we can see these newer high tech diesels, we need to create the legislation (within the EPA/CARB) to require that the quality of diesel sold in America meet the minimum quality standards required in the rest of the world. For example, the new ULSD (Ultra-Low Sulfur Diesel) fuel does not meet the European or Asia standards for diesel fuel quality required 10 years, let alone today.

Ethanol, Bio-Diesel, Propane, Natural Gas, Methanol, Electric-Battery, Solar, among a small list of others, are all quant and interesting, but none of them are viable or practical and some are even worse, environmentally, than gasoline, but a switch to diesel now and then eventually over to Hydrogen is really the only answer.

SteveC

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I just want to know when companies like audi, volvo, and vw will stop talking about it and actually release a new tdi into the US market. I like hybrid technologies. However, I think that as a longer term investment tdi is still the way to go. I hold on to my cars for 10+ years and really dont want to get stuck buying a 7K or more battery pack. If the a3 was available in tdi I would drive down to my local audi dealer and buy one immediately.

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Lets move on from 10 year old hybrid gasolines supposedly being green!
Last 5 years I've driven an Audi A2 1.2 TDI - she returns 93 (uk) mpgn and emits 81 to 86 g/km CO2 (new prius is 104 g/km by the way). even at an average of 91MPH on the Autohbahn A2 will return some 66(UK) mpg! And that TDi technology comes from Elsbettt in the 1970s!

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