I just encountered a typical lay media puff piece about the 2009 diesel Jetta, which won the Green Car award this year.
Did you know that the next generation of diesel-powered cars and SUVs is 98 percent cleaner than diesels sold just two years ago?
No, but I also didn’t know that the older models were that dirty!
Did you know these new clean diesels offer 23 to 43 percent better fuel economy than the same vehicle with a gasoline engine?
Sounds impressive! Until you go to the EPA green vehicle website and discover that the gasoline version with a standard transmission gets an air pollution score of 9 compared to this car’s 6.
This car does get a higher GHG score, but if you accept the findings of the Union of Concerned Scientists that a gallon of diesel creates 17 percent more GHG during the refining process, then the GHG score drops to 7, making this car no better than the $17,400 gasoline version in this category.
And finally, did you know this new generation of clean diesel-powered vehicles offers efficiency matching that of gas-electric hybrids?
Again, going to the EPA website and comparing this car to its closest competitor, the Prius, you find the Prius gets an estimated 65 percent better city mileage and 10 percent highway. How can you call that a match? Maybe they were referring to the Cadillac hybrid.
To compare it to a Prius, which is a hatchback with automatic transmission, I would need to take the $1,600 wagon and the $1,100 dual clutch options, driving the price to around $24,700. It has been predicted multiple times on the blog that the introduction of low sulfur diesel would eventually allow somebody to market a diesel here that meets air pollution standards in all 50 states. It was also predicted that this car would be complex, expensive, and have the attendant engineering compromises:
That said, it’s clear the TDI was designed to perform at the pump, not on twisting back roads ...
The car is rated to accept up to a 5 percent blend of biodiesel, but even if you have a source that uses waste, a 5 percent blend won’t overcome the 17 percent refining penalty. You would need to be willing to risk your warranty and go to a waste biodiesel blend higher than 17 percent to coax this car to be greener than its gasoline cousin. Don’t hold your breath for algae-based biodiesel. According to this recent relatively balanced article, it remains perpetually a mere five years from viability (h/t the inestimable Mr. Steenblik).
This is definitely a good-looking high-mileage car. Compared to most other cars on the road, it is a real winner. They just need to stop comparing these diesels to equivalent-sized electric hybrids. Diesel technology is tapped out with this car. The electric hybrid concept is just getting started.
Capturing the massive social benefits of fuel efficiency requires regulation
Comments
View as Flat
Sam Wells Posted 10:54 am
06 Jan 2009
So that's an astute comment and yes, the Jetta is better than owning a SUV but not as good as an urban assault vehicle, which I laughingly call a UAV because they're always crashing into one another. I suppose a hybrid or plug-in UAV would be the best fun, right?
But as I have said several times, the heavy-duty component is something to be treated very seriously if we want to win the war on Global Warming. Some estimated that the large ships of the world, perhaps only numbering 50,000, comprise slightly over 5 percent of the CO2 emitted to the atmosphere, without considering any refining (ship fuel is not very refined, but low sulfur is being required more and more). If you add together all the diesel/distillate powered transportation sources such as ships, planes, trains, and trucks, now you're talking some major Mojo.
In that context, a couple of VW Jettas on the road seems rather silly, especially when the 40 ships a day that visit the Ports of Long Beach and LA emit more than the entire transportation sector.
We've got a long way to go, Pilgrims.
Onward through the fog
Permalink
hapa Posted 11:05 am
06 Jan 2009
That said, it's clear the TDI was designed to perform at the pump, not on twisting back roads ...
what was said:
That said, it's clear the TDI was designed to perform at the pump, not on twisting back roads, as evidenced by the immediate desire of the stock 205/55R16 rubber to relinquish its feeble grip on the asphalt. The brakes make a similar statement when jammed on before a tight corner ("Please stop driving like this"). Despite this, the Jetta TDI is quite fun to drive aggressively, thanks to a well-tuned suspension and good steering.
"quite fun to drive aggressively"? is that the "attendant engineering compromises" you're talking about?
the brakes are probably standard non-sport jetta, no reason to have changed them. the tires are the difference but even so, by hunting around on the net for reviews, as one would expect, the grip, control, power, and handling feel of the jetta are all much better than the "car of the future" prius.
(i agree with the green-ness, operating cost, and interior design comparisons.) (except for comparing refinery footprint while omitting battery manufacture byproducts.)
i'd really rather read a showdown between a prius and a train.
Permalink
Tasermons Partner Posted 12:41 pm
06 Jan 2009
Be careful of percentages alone. They can be tricky to those who would not look at the bigger picture.
For example, Hospital A says that their survival rate for trauma patients has increased 100% in the past decade, while Hospital B survival rate has increased only 20%.
Obviously Hospital A is the better choice...
...until you find out that Hospital B had a much higher recovery rate to begin with, and treats many more people than Hospital B.
Or, for another example, Forestry Group A says that they've increased the nuber of trees they plant by 1,000% while Forstry Group B has only increased by 20%
Obviously 1,000% is the way to go...
...until we learn that 1,000% of an original single tree planted equals only 10 trees, whereas 20% of a million trees planted equals 200,000 trees.
So while percentages are important, it's good to look at all the numbers as well.
Permalink
dieseldude Posted 2:08 am
07 Jan 2009
That said, the facts are there for anyone willing to drive the vehicles discussed, selective or otherwise: Jetta delivers real world fuel economy comparable to the Prius with significantly better real world performance.
Greenness has several different measures, but the CO2 reduction of a modern diesel cars (which meets the same tailpipe emissions standards as a gasoline version) is clear. We need to use every tool in the shed.
Commercial aside: Note the Prius ad at the bottom of the page of this post. Who's paying the bills at Grist?
Permalink
dieseldude Posted 2:10 am
07 Jan 2009
Permalink
biodiversivist Posted 2:46 am
07 Jan 2009
Though 30-horsepower weaker (at 140 hp at 4000 rpm) than its European cousin, this new TDI is a lot cleaner.
Which may also be a seen as a selective quote because later he says "Despite the choked exhaust system, the engine still manages to belt out 236 lb-ft of torque ...". The Prius can belt out 352 lb-ft, depending as always on RPM.
This post was not meant to degenerate into the classic Jetta Prius pissing match. I was just clarifying the cars green credentials. It has a lot of advantages over a Prius if those advantages are important to you. You can't tow anything with a Prius.
It also has, among other things I'm sure, better rear visibility than the Prius and better road clearance. Fill it up with waste based biodiesel and it would also be a very "green" car, whatever exactly that means and assuming there is such a thing.
Acceleration and torque are tied together. Acceleration is most important when merging onto a highway or when passing. All that matters is that your car has "adequate" torque, which is also true for speed. Top speed along with excessive acceleration potential are irrelevant in my book but some guys think they are, even though they will never actually experience either.
The "quite fun to drive aggressively" remark in the review cracked me up. Seems to me that if you want the thrill of taking curves at high speed, you should do it in some beater that you wouldn't mind crashing, or a maybe a wheelbarrow, or better yet, just ride a roller coaster.
We are all victims of marketing hype to different degrees. The sport utility deception will go down in history as one of the most successful. Marketing cars to guys is an art form. We're just too vulnerable on too many fronts. We have the hard as a rock, Chevy Silverado and Avalanche, the Dodge "Ram" series with their "hemi" and on an on.
All cars have to pass safety tests. As far as handling goes, I'm happy if it accelerates safely onto highways, stops when I stomp the brakes. Power steering and brakes are nice. Handling characteristics "the grip, control, power, and handling feel" after a point are mostly subjective and mostly marketing gimmicks to get guys to imagine themselves as James Bond, "driving aggressively" down a curving mountain road with Olga Kurylenkoin the passenger seat.
Most dust to dust studies suggest that the footprint associated with making and recycling a battery is compensated for by the increase in efficiency imparted. The one study that said otherwise has been largely discredited. The Jetta also didn't fare much better than the Prius in that study.
By the way, check out this Prius doing a speed run ; )
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
Permalink
biodiversivist Posted 3:00 am
07 Jan 2009
dieseldude,
Glad you got that off your chest and I wasn't aware that this was a press release. Thanks for the info.
I suspect diesel technology is near its peak, just as reciprocating engines reached a peak with aircraft during WWII. Some engines had 48 spark plugs, water injection, turbo chargers, mechanical exhaust power collectors and all had thousands of moving parts all jerking to and fro and reversing direction thousands of times a minute.
Then along came the turbine engine with one rotating part.
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
Permalink
dieseldude Posted 8:26 am
07 Jan 2009
Michael
Permalink
biodiversivist Posted 9:30 am
07 Jan 2009
Another analogy. To get more horsepower out of WWII aircraft engines they turbocharged them, which was especially effective at altitude. That spinning turbine bolted to the recip engine evolved into a jet engine. The electric motor bolted to today's hybrids may take over as well.
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
Permalink
dieseldude Posted 11:22 am
07 Jan 2009
Michael
Permalink
hapa Posted 2:03 pm
07 Jan 2009
obviously though i like a well-balanced car and for both of the cars i've owned there were a couple years at the start where i took it into the hills and threw it around, mostly to learn how it handled under pressure, in detail; how to drive it smoother at speed; but it was also very entertaining, even with my patented "this is not a race track keep your head on" approach to twisty roads.
when i learned driving there were precious few cars with any CYA technology for the brakes or wheel spin. it was very important to understand how a car handled and also that a car be good at accident avoidance, with or without proper driver input.
having also driven a recent jetta, i guess all of this is to say that -- driving defensely being very important for health and gas mileage both -- i'm sure i'd survive a fast-changing dangerous situation on the road in either car -- but the jetta feels more capable of evasion in the hands of a driver who knows what they're doing.
Permalink
biodiversivist Posted 1:07 am
09 Jan 2009
"In this corner, weighing in at 5,683 pounds is the reigning world champion, the Ford-F-150, hailing from Dearborn, Mich. Standing in the opposite corner is the No.1 contender, weighing in at 5,548 pounds from Warren, Mich., the Dodge Ram 1500"
http://fp.images.autos.msn.com/media/425x255/89/89e01dfea3a243f09ca977d2826cd8ee.jpg
My grandma could drive one of these. They have power everything. Eight out of ten of them will be sold to guys who will use them to commute to their jobs in factories or offices and to haul the occasional bag of beauty bark from the hardware store.
It's marketing. It's image. It's status seeking. Change status symbols. Real men drive high mileage cars ; )
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
Permalink