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.

— w209w114 (View Profile)

Posted on 7/5/2007 10:07:35 AM | reply to this comment | Votes: 4   

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

— jeffy210 (View Profile)

Posted on 7/5/2007 10:23:46 AM | reply to this comment | Votes: 4   

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.

— johannas (View Profile)

Posted on 7/5/2007 10:46:28 AM | reply to this comment | Votes: 4   

Why not post your counter points to it then?

— Agent009 (View Profile)

Posted on 7/5/2007 10:54:02 AM | reply to this comment | Votes: 2   

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)

— chewy (View Profile)

Posted on 7/5/2007 5:26:45 PM | reply to this comment | Votes: 3   

Agree. See my comment below.

— EnnNorak (View Profile)

Posted on 7/6/2007 8:52:52 AM | reply to this comment | Votes: 3   

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..

— SevorbeupstryIsBack (View Profile)

Posted on 7/6/2007 11:01:32 AM | reply to this comment | Votes: 2   

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.

— cthip (View Profile)

Posted on 7/5/2007 11:48:47 AM | reply to this comment | Votes: -2   

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...

— Will_ (View Profile)

Posted on 7/5/2007 12:33:49 PM | reply to this comment | Votes: 2   

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.

— chewy (View Profile)

Posted on 7/5/2007 2:19:43 PM | reply to this comment | Votes: 2   

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.

— consaka (View Profile)

Posted on 7/22/2007 2:35:02 AM | reply to this comment | Votes: 1   

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.

— 1970toyotamarc (View Profile)

Posted on 7/5/2007 3:55:35 PM | reply to this comment | Votes: 0   

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?

— EnnNorak (View Profile)

Posted on 7/6/2007 8:51:42 AM | reply to this comment | Votes: 2   

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.

— norak (View Profile)

Posted on 7/6/2007 11:11:06 AM | reply to this comment | Votes: 1