Volkswagen diesel car wins "Green Car of the Year"

Yup, that's it, thanks!

 

Look at what it takes to make gasoline cars cleaner! The only reason they are cleaner today than diesel vehicles is because of the Californian CARB regulations kicking in from the 70s. The automakers fought against it tooth and nail, but eventually had to develop all of the exhaust cleaning technologies used today in gasoline engines.

Back then, diesel cars had much, much *LOWER* NOx and CO emissions than gasoline cars, which spewed horrible amounts of pollutants into the smog. Without any exhaust treatment, the diesel engine is inherently cleaner than the gasoline engine. As a result, diesel cars were sold on their eco-credentials, being lower emitters of NOx and CO.

However, since the USA used gasoline almost exclusively, the automakers focussed all their energies on cleaning up gasoline exhausts. It cost BILLIONS in R&D, and in the end they had to resort to using very sophisticated emissions control systems and some of the rarest and most expensive metals on earth, ie platinum and rhodium, to make the catalysts work!

Only in the last five years or so have automakers started shifting towards cleaning up diesel exhausts, so some lag should be expected. However, there is absolutely no reason why a diesel can't exceed Tier 2 Bin 5 or SULEV regulations, even without resorting to urea injection or SCR etc: Green Car Congress: Ricardo Announces Demonstration of Tier 2 Bin 2 (SULEV) Diesel

This is not correct. A gasoline vehicle is very innefficient at cold temperatures, as it must run "rich", wasting lots of fuel. This is why the Prius has its coolant thermos.
On the other hand, a diesel engine does not need to "run rich" from cold, and is therefore much more efficient when starting from cold than a gasoline engine. Stop/start systems on diesels also work very well (like on all BMW active dynamics diesel vehicles).

 

PLEASE READ THE POST BEFORE REPLYING!

If you notice I was comparing gasoline engines with diesel engines of the same power (HP, KW, PS) Yes, they have the same power and diesel has more energy but the diesels also have way for torque.

Again, please read my post. I AM comparing the TSI (Gasoline) to the TDI (diesel) Both use common rail, direct injection. Both use forced induction (turbocharged) The TSI (gasoline) engine has both a supercharger and turbocharger. It uses the supercharger to produce low RPM boost. At middle rpm's is engages the turbo at low boost and they both are working. At high rpm the supercharger disengages and the turbo takes over at high boost.

The petrol engine has direct injection, forced induction, egr, catalyst. (no particulate filter)
The diesel engine has direct injection, forded induction, egr, particulate filter (no catalyst)

I am comparing the same company, same vehicle, same HP, same technology level. The difference is one is fueled with gasoline the other with diesel

Again look at the engines. The difference is the gasoline car has a catalyst and the diesel a particulate filter. The rest of the technology is the same. For Euro V emissions gasoline cars with direct injection must be tested for particulates. For Euro VI all cars regardless of fuel will be tested for particulates.

The Golf Sport TSI is 18,980 UK pound
The Golf Sport TDI is 18,970 UK pound

So the diesel is 1K more but has 20% lower fuel consumption.

 

Jhinton,

The Prius wallops the VW diesel offering if we look at any emission in grams/distance. What are we arguing about again ?

 

No, the site I linked shows N/A (not applicable) because Euro 4 and Euro 5 emission regulations don't require gasoline (petrol) engines to be tested for particulates. US EPA and CARB regulations don't require testing for particulates either. As I said, just because you don't test for them doesn't mean they don't exist.

I have some questions about the emissions tester you used in Portugal. Is it a emissions lab as used to certify engines for manufacturers or little station used to certify vehicles for yearly inspections?

What technology are you using to test for particulates? Three possibilities come to mind.

1) Opaque testing: a sensor measures the color of the exhaust gases. This only checks for visible emissions

2) Filter testing: emissions are passed through a filter and then weighed to see how many grams of particulates are accumulated. This type of testing is completely dependent on the size of the filter mesh. Most are only designed to catch particulates P10 and greater.

3) Particulate count: The newest type of testing where a very high speed camera counts the particles.

Euro 6 testing will most likely be a combination of 2 @ 3. I suspect your testing equipment is the first type.


Again, do the easiest test possible. Stick your finger in the tailpipe. If it comes back clean your Prius truly has 0 PM emissions. If it comes back black as it will, you will find you do have PM emissions.

Don't need to, the data speaks for itself. Just fighting misinformation like "my Prius has no PM emissions".

 

I don't argue that. I disagree with the blanket statement here on Prius chat that diesel engines are dirty polluters and gasoline engines are clean. That is why I've posted the information comparing non-hybrid engines.

Part of the reason that hybrids have such low emissions is because the hybrid system allows the vehicle to move with the engine off. Any time the engine is off you are recording 0 grams / mile and greatly helping the average.

 

I seem to be missing something here. The CARB tables I have on my computer seem to require PM and hydrocarbon measurements for certification.

I said earlier, but perhaps you missed it, that city driving in a Prius has higher emissions overall than highway driving. Look here:
http://www.ctts.nrel.gov/analysis/hev_test/data_prius.shtml

Code:

Measurements in gram/mile
HC         CO           NOx
0.009     0.116       0.003   FTP Cycle
0.001     0.09         0.008   HWFET

 

Not really - don't forget that any energy you take from the battery is only a loan. Later on it will have to be paid back by the engine working harder when it is running.

kevin

 

Euro Emissions Standards. Table from
EurActiv.com - Euro 5 emissions standards for cars | EU - European Information on Transport & Services

 

jhinton, please, let's get serious here, will you?

You can find particle measures on the Prius and on other gasoline cars all over the internet. Most readings are "bellow measurable values", what's your point?

Of course there is some dirt coming out my tail pipe, never said it did not!
I'm only saying that the dirt and the gases that came out of a diesel tail pipe are hundreds and some times thousands of times more and more dangerous to your health and the environment. The data speaks for itself.

You pick the gas emission you want, pick anyone at random, pick your best "eco-friendly" diesel you want. I will put my Prius against it and it will bust your diesel to a ridiculous stand. That's the only thing I'm arguing here.

I already pointed and listed the emissions on one of the best diesels, the VW Golf Bluemotion released this year. Even that one is far worse than the Prius which is already several years old. Why did you not comment on that? Are you only concerned with PM? Even in PM do you have any doubt that diesels emmit thousands of times more PM than gasoline???

What's the matter with you? What is your problem? You are arguing against the Prius on a Prius forum where all the scientific evidence is against you! What is your point? Are you selling diesels or what???

 

Very good link, thanks a lot SageBrush!

Let me quote this one which is one of my strongest points in all my arguments about diesels and the way they pollute our European space:

<begin quote>

Emissions of the highly noxious pollutants known as nitrogen oxides (NOx) and particulate matter (PM) from diesel vehicles are currently four to five times higher than for petrol vehicles. The Euro 5 Directive aims to make diesel cars "catch up" - although not completely.
The Euro 5 limits will reduce emissions of particulates from diesel cars by 80% compared to Euro 4. They will however be more lenient as regards NOx emissions, which will only have to be cut from 250mg/km to 180mg/km – against the current 70mg/km for petrol vehicles.
This leniency for diesel vehicles contrasts with legislation in the United States, which is "fuel-neutral". However, it is worth mentioning that diesel cars represent roughly half of all cars in the EU, whereas they represent less than 5% of those in the US.
<end quote>

So, roughly half of our cars are polluting like hell, and we do it because in most European countries (like here in Portugal) diesel is in fact a lot cheaper than gasoline.

Talk about a deadly combination...

 

So far as I can tell, US federal standards have also required PM measurements --
0.1 grams/mile is equal to 6.7 mg/km for T2B6 and better. Euro IV requires less than 25 mg/km in diesels.

 

Only direct injection petrol (gasoline) engines have EU particulate requirements.

Emission Standards: Europe: Cars and Light Trucks
Look at note d under table 1

European emission standards - Wikipedia, the free encyclopedia
Look at note ** in European emission standards for passenger cars

 

I'll stand up for Jhinton here. He argues based on data and not silly partisanship. You and I may disagree with how it interprets the data, but there is room for civil argument in this context. OK ?

 

I agree Re: Euro I - IV. But CARB and US Federal Tier II *do* measure PM, right ?

 

I'm not debating that a Prius has lower emissions than any diesel vehicle. If you looked at my post I was comparing conventional gasoline vehicles to diesel vehicles.

I do dispute that a Prius has 0 particulate emissions. I have never been able to find actual test data on a Prius that shows particulates. Why, because they aren't listed on EU or US test results because testing for particulates is not required. All you will find is N/A. Now for a diesel vehicle with a particulate filter it will say 0.000 but gasoline vehicles say N/A. If they did the testing on a gasoline vehicle why not just put 0.000 instead of N/A?

You did say that you tested your Prius and it had 0 PM. I simply asked how it was tested.

Why am I on PriusChat? I have a Prius of course. I also have a VW TDI. I think that hybrids, diesels, DI, turbocharging, EV's and many other technologies will be needed to reduce our societies dependency on oil.

 

Jhinton, I don't understand why you say that Prius has not been tested for PM. It seems pretty clear to me that it is required for CARB 120k mile SULEV certification.

 

No

Here is CARB 2009 VW TDI: http://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2009/volkswagen_pc_a0070271_2d0_l2_diesel.pdf

PM CERT (actual measured data) is listed as 0.000
PM STD (max allowed by standard) is listed as 0.01

Here is CARB 2009 VW Prius: http://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2009/toyota_pc_a0140628_1d5_pz_hevge.pdf

PM Cert is listed as *
PM STD is listed as .01

 

Fair enough, but that's not my point.

My point is that there is an underlying statement that reads "diesels can be as clean as hybrids" or at least "diesels can be clean", and that I absolutely reject and scientific evidence proves wrong, no matter what Jhinton or you or me may think.

By all counts diesel cars are the worst polluters at the face of the earth, just looking at their emissions is frightening as hell. How can someone who owns a Prius, the cleanest ICE vehicle on earth defend diesels is something that bugs me.

Someone that cares for the environment and cares for public health will hate diesels for sure if he learns what diesels put out the tail pipe. Just google for diesel emissions and search for medical research documents and you'll find a whole universe of evidence of what diesel does to your body.

I'm not going on a silly partisanship about Toyota or the Prius for that matter. I love the Prius for being the best car available now for what I need in a car. I love the Prius for showing the world how clean a car can be even without being EV. I hate the diesels for the opposite reason.

Focusing this whole discussion on PM and on the fact that the Prius has or has not measured PM data is completely absurd. First of it is absurd because no matter how you measure PM on a Prius, it will always be infinitely lower than on any diesel, even with PM filter fitted. The kind of small particles that get out on the Prius also get out on any PM filter, they are very small.

Last but not least it is absurd because the PM is only part of the problem. Ignoring the other gases, all the other stuff that cames out of diesels alone is looking the other way on all the major poisenous gases that kill you and me everyday.

This is just my two cents worth of opinion, and frankly I feel like I have posted my point of view well enough for everybody to understand. Anyone is free to agree or disagree of course.

I just don't understand how can anyone support diesel cars, it's like supporting cancer. In fact diesel is one of the major causes for cancer, now that I mentioned this...

 

Good links, thanks. I agree that the PM results are less than clear, but PM *is* a required measurement for gasoline cars. I'm not sure about diesel.

Do you have links to the US federal equivalent ?