The Truth About Diesels

"No wonder the Germans are so gung-ho on sending their diesels across the pond"

Agent009: If it was in-fact the way you state it, then there wouldnt be much new diesel production or development. We all know Diesel is now as popular as ever. Inflamatory statements like that are only meant to start flame wars and pointless discussions.

I am a diesel advocate, but I also post all viewpoints whether I agree or not.

While I don't agree it is a valid counterpoint.

Wow, too bad there's no way to mod a whole story down. This is purely meant to incite a flame war.

The author of the article may have been run over by a diesel as a child. That might explain his disposition.

He also left out the fact that diesel engines were designed to, and still can, run on vegetable oil. This fuel source might not be cost effective today, but the ability for diesels to run on an alternative energy source is promising.

Sounds like a possibility to me.

Why not post your counter points to it then?

Let me go point by point.

The Germans are sending cleaner diesels to US than they have at home, so from the begining the article makes no sense.

I think it makes sense to assume that a Bin5 diesel will produce no more particulate matter than a Bin5 gasoline engine. I am sure the new TDI tailpipe will be squeaky clean with zero black stuff on it (some new gasoline engines have grimy exhaust pipes)

The PZEV Rabbit is cleaner than many Priuses sold. The new TDI will still be way more efficient than the current unit. The next gen Prius is not out yet.

Diesel efficiency did not peak in 1989. It has only risen since with use of common rail/piezo injection. And common rail technology has improved as well, with the newest 2,000 bar injection pressure improving upon the 1,600 bar.

I estimate that the 170 hp common rail TDI will only produce around 150 grams of C02. The 204 hp version in the all wheel drive Audi concept was rated more fuel efficient than the 170 hp PD version of the Golf GT. (sidenote, the US 2.5 Rabbit is not giving up gobs of torque, currently it is only down 7 lb-ft and the 170 hp version will have the same exact torque amount. But it shows how much more fuel efficient the TSI is compared to the 2.5)

Why an 170 hp diesel to a 78 hp Prius that has special aerodynamics. Might as well bring up the fact that the Polo Bluemotion also only spits out 102 grams of C02. Not to mention that the Prius actually produces 104 grams of C02, I bet he got the 102 figure engrained from the Polo Bluemotion.

You can put mild hybrid technology onto a diesel as BMW is doing with one of its diesels in the 1 series (start-stop)

Agree. See my comment below.

I agree with cawimmer here.. this article is way off. They are speculating things that were speculated years ago and still they haven't happened..

so what's new?

even clean diesels still pollute more than hybrids and some of the more efficient gasoline engines.

that doesn't change the fact that they get great gas mileage, diesel is generally cheaper than 87 octane in the US, and provide better low to mid-range torque for everyday driving.

if you're a hardcore environmentalist, sure buy a hybrid (and conveniently overlook the environmental impact of production and disposal of all those batteries). for the rest of us, we can only hope we'll see more diesels in the US. we'll all save a few bucks and have much more satisfying machinese to drive.

The thing that everyone tries to push into the corner is that diesel technology is not as clean as hybrid technology when it comes to emissions. There's no getting around having to add filters to diesel cars to make them emit not even as low as most comparable hybrid setups. I'll take the combination of gasoline and electricity over diesel and filters. Now diesel and electricity would be a different story...

Need I also bring up again the recycling program that Toyota has in place and that hybrid batteries are recyclable anyway?

So little correct information there. All European diesels are being retrofitted with particulate filters IIRC. The common rail 2.0 TDI will have oustanding fuel economy and emissions figures.

Particulate emmissions are the main thing people make a big deal about but they aren't that big of a deal. Particulates are mostly carbon with some wax compounds left over. If your body is working correctly your nose can filter those particles just like it does all the other junk you breath everyday. You are in more danger of getting sick standing on the same acre with a cig smoker then with a diesel. Supposedly clean gas cars still give me a headache with their exhaust. takes hours for it to go away.

If a hybrid cant beat 31 mpg then its got problems. However I believe those diesels are full size cars right? The ones you would be more likely to survive a crash in.. I love bio-diesel.. thats great stuff.

Sifting through the many comments on the original article gives some great points and counterpoints from people on both sides who seem to have done a lot of research and put a lot of thought into their arguments.

For my two cents, I'll add that what strikes me most about the debate between the two engines is the claim that diesels are nearing the maximum outputs/efficiency/cleanliness we can wring from them. Meanwhile gasoline engines, notably with elctric hybrid motors, are in a development boom.

With direct injection (no hybrid), we're seeing V-6s getting over 300hp, while still returning mpg in the 20s and being rated ULEV. example- http://www.lexus.com/models/IS/detailed_specifications.html

For emissions, 4 and 6 cylinder engines are being tuned to produce PZEV ratings.
For a PZEV list, take a look at http://www.driveclean.ca.gov/en/gv/vsearch/cleansearch_result.asp?vehicletypeid=16
I think you might be surprised by some of the vehicles on the list. Many of the cars are giving you PZEV emissions without sacrificing performance or mpg.

Now add hybrids to the mix, which are just in their infancy. It doesnt take a rocket scientist to extrapolate the potential here.

I say bring on your clean diesels. In fact, I'm sure the next Honda and Toyota diesels will be great compared to today's and yesterday's. But meanwhile gasoline and gasoline/electric hybrid vehicles will continue to advance by leaps and bounds.

I really don't think we are nearing the peak of diesel technology - a lot of the "new" petrol technologies are just diesel techs (direct injection, turbos), and I still think diesels can get even better, engineers are aways improving, and as diesel fuel contains more energy, it is logical that a diesel will ALWAYS be more fuel efficient than gas. Hybrid tech doesn't just improve gas technology, it can be applied to diesels too - imagine a BMW X5 3.0 TT diesel hybrid - 30 US mpg easy, perhaps 35. And of course as hybrid becomes cheaper, it becomes even more economically viable to make a diesel hybrid. I'm sure there are many people willing to pay an extra 4000 dollars for a diesel hybrid X5 type vehicle.

These 300hp V6s - look at the 535d. 3 litres, twin turbo, 286hp and over 30 US mpg. A GS450h, never mind a GS350 is able to match that.

What I want to see is a Prius with the 2.2 hdi from PSA, I want to see how much of the fuel efficiency and low emissions is owed not to the hybridness but to the special construction with light materials and good drag coefficients.

What we have to remember is that diesels are a lot cheaper than hybrids, and until the next Prius comes around, we won't know the fuel efficiency or performance or pricing. So for now, and for the next 2 years, diesel still holds its crown. For the future, I believe it still will for the next 10 years minimum, and diesel hybrid will only strengthen its hold.

Thats funny.. I found this article to be full of sensationalism. Very Light on the facts.

Perhaps this author receives financial contributions from companies who have a vested interest in competing technologies. Modern diesels have virtually eliminated all the negatives of diesels half a century ago. If one technology is 1% or 2% better or more efficient in some respect, who cares?

Where I live, a diesel car is not worth it because they tend to be more expensive to buy. Even if you get better fuel economy the average person will not be able to make the money back.

Fuel economy is not the prime motivator for me. I want a diesel because of the high torque (mountain driving advantage) and long range for distance driving. BTW, I note you use the moniker "norak". Are you the same guy that once picked "norak" for an internet e-mail address because you were a Treckie and thought that "norak" sounded like a good Cardasian name?

Sooo? Diesel sound better LOL