My diesel gets better MPG than your hybrid

Those Jetta are not bad, well a 96 is, but they are smaller, and they are expensive. They are a good deal if you can get free cooking oil to burn. In a smug contest Jetta driver win hands down to prius drivers, both are trashed by the smug level of the i ride a bike to work people.

 

<div class='quotetop'>QUOTE(clearview22 @ Aug 6 2007, 07:58 PM) [snapback]491365[/snapback]</div>

For city driving, an automatic gearbox (or even better, the CVT of the Prius) is by far preferable indeed.
But, driving on curvy country roads, a manual transmission is so much more fun to drive.

 

<div class='quotetop'>QUOTE(RinMI @ Aug 6 2007, 09:14 AM) [snapback]491200[/snapback]</div>

Who says a Diesel Jetta isn't clean? I find the EPA Air Pollution score to be misleading at best. Why? Because it is only based on the maximum allowed emissions from the Bin the car is put in instead of the actual EPA certification data. While this may work find for similar gasoline vehicles it doesn't do well when comparing diesel vehicles to gasoline vehicles. Again you may ask why? The reason is that diesel certify significantly lower that their classified bin in every category except NOx. This will be especially true of 2008 diesel with emission control and exhaust aftertreatments. Take my 2003 VW TDI for example:

Standard------NOx----NMOG----CO----PM------HCHO
T1 Diesel------1.25----0.310----4.2----0.10-----None
(Effective from 1994 to 2003)

2003 1.9L TDI Actual EPA Certification Data
----------------NOx---NMOG----CO---PM---HCHO
----------------0.7------0.02*--0.2---0.05---N/A

Notice that the Actual Certification data is significantly lower than the standard for all emissions tested.

Now lets look at present Tier 2 standards and see how it compares to what you can buy today:

Standard-----NOx---NMOG---CO---PM---HCHO
T2B1---------0.00----0.000----0.0----0.00----0.000
T2B2---------0.02----0.010----2.1----0.01----0.004
T2B3---------0.03----0.055----2.1----0.01----0.011
T2B4---------0.04----0.070----2.1----0.01----0.011
T2B5---------0.07----0.090----4.2----0.01----0.018
(Effective from 2004 on)

So from the actual certification data the 2003 TDI is:
NOx:-----Tier 2 Bin 5
NMOG:---Tier 2 Bin 3
CO:------Tier 2 Bin 2
PM:-------Tier 2 Bin 9
HCHO:----- Not Measured

So the only thing keeping a 2003 TDI from being sold today is PM. The same engine was used in the US from 1996 to 2003 BTW. I would say that is pretty good for technology that is 15 years old.

To compare it to a contemporary Hybrid here is the Civic Hybrid:

2003 Honda Civic Hybrid
----------------NOx---NMOG---CO---PM---HCHO
----------------0.1-----0.016---0.8--- N/A---0.3

So the Civic puts out 7x less Nox but 4x more CO2. Pick your poison.

As far as mileage look at my signature. That is my record mileage for the last 9 months in mostly suburban driving. In my experience the Prius does better in town, the TDI down better on the highway.

My experience:

TDI:
City 40-44 mpg
Highway: 50- 55 mpg
2008 EPA 35/39/45

Prius:
City 47-50 mpg
Highway: 46-48 mpg
2008 EPA 48/46/45

As you can see the TDI does significantly better than the EPA estimate which makes comparing their barrels of oil charts pretty useless.

 

<div class='quotetop'>QUOTE(vtie @ Aug 6 2007, 03:00 PM) [snapback]491414[/snapback]</div>

Yep, you can always tell a manual trans driver by the way they walk, always compensating for the pull to the right, overdeveloped left leg from pushing that clutch in.

 

When I read the title of this thread, I had a vision of someone walking on the roof of a Jetta. (Sorry, the grammar police made me do it!)

 

<div class='quotetop'>QUOTE(Slair @ Aug 6 2007, 12:35 PM) [snapback]491395[/snapback]</div>

The novelty wears off after you've done it for more than a quarter of a century.

I drove stick shift for the longest time for a number of reason. Something to do with better fuel economy and I just never liked the mushy feel of the old automatics.

But after driving stick for the last 25 years, I knew my next vehicle was not going to have a stick-shift and clutch. The Prius fills the bill very nicely.

 

As you can see the TDI does significantly better than the EPA estimate which makes comparing their barrels of oil charts pretty useless.
[/quote]

I do not keep up on Honda Civic hybrid numbers. The Civic and the Prius are not the same. The Civic hybrid is a hybrid package placed in an existing model. The Prius is a vehicle built around the hybrid package. Not saying one is better than the other, jsut noting the differences. My Prius (and every other 2004 and later) qualifies for the SULEV standard. If any '96, '03, or even an '08 Volkswagen (TDI or not) qualified for this rating Volkswagen would be advertising the heck out of it.

The fact is that diesels, in the arena of exhaust emissions are inherently dirtier than gasoline fueled vehicles, just like ethanol fueled vehicles are cleaner still in the general sense of overall exhaust output.

Once again, I and many others bought the Prius not just for fuel economy but also for it's cleanliness. When someone wants to force the discussion to devolve into an argument over fuel economy, it is no longer worth trying to convince them. Most people fall into one of two categories; people that will not change their minds regardless of what evidence is presented to them, and those who sincerely have an open mind and want to learn.

 

<div class='quotetop'>QUOTE(jhinton @ Aug 6 2007, 04:26 PM) [snapback]491472[/snapback]</div>

Well, since NOx is supposed to be worse for the environment than CO2 and considering that 7 is bigger than 4 I think losing NOx is the most logical choice here.

 

"Snooty?" Just use your index finger to write "sooty" in the black stuff that's probably caked on his rear bumper.

 

<div class='quotetop'>QUOTE(RinMI @ Aug 7 2007, 09:08 AM) [snapback]491797[/snapback]</div>

You either didn't read my post or entirely missed the point. Yes, our Prii are classified as SULEV. You must live in a CARB state since you are using the CARB classification instead of the EPA classification. My point was the classification system is misleading because the vehicle is classified by the worst emission.

Say you have two cars:
Car A meets the exact maximum standards for all 5 classes of pollutants to be classified as SULEV
Car B has 0 pollution in 4 classes and the maximum standard for 1 class to be classified as LEV

You and the EPA would say the Car A is cleaner because it is classified to a "cleaner" standard. (The EPA would give Car A a 9 for it's Air Pollution Score and Car B a 6)
I would say that car B is cleaner since it emits less pollution than car A.

You are right that the new 2008 TDI will not be SULEV. I will have too high of NOx emission to meet that standard and will be T2B5. But all of the other measured pollutants will be MUCH lower than T2B5 levels.

Lets compare actual CARB certification data to see what car are really cleaner.

Car------------------NMOG----CO----NOx-----HCHO-----PM---Classification---Total g/m ----Total Allowed by Class
03 Prius-------------0.003----0.4----0.01-----0.02------N/A----LEV II SULEV----0.730----------1.044
03 Civic Hybrid-----0.016----0.8----0.10-----0.30------N/A----LEV I ULEV-----0.496-----------2.466
03 Civic CNG-------0.001----0.1----0.01-----0.10------N/A----LEV II SULEV----0.211----------1.044
03 Insight-----------0.023----0.6----0.10-----0.50------N/A----LEV I ULEV-----1.223-----------2.466
03 Jetta 2.0 Gas----0.006----0.7---0.003----1.0--------N/A----LEV II SULEV----1.709----------1.044
03 Jetta 1.9 Diesel--0.020---0.2----0.70-----N/A-------0.05---Tier 1 Diesel-----0.970----------5.860

So you can see that actual emissions can vary quite a bit within the EPA or CARB classifications. While the TDI is putting out 33% more emissions than the Prius it is only emitting 17% of what it is allowed to by it's classification while the Prius is emitting 70% of it's allowed pollution. So you can't just use the EPA's air pollution score which assumes the Prius emits 1.044 g/m and the TDI emits 5.860 g/m if you want a realistic comparison.

Notice that the TDI is cleaner than it's gasoline counterpart and the Insight. So much for you blanket statement that "The fact is that diesels, in the arena of exhaust emissions are inherently dirtier than gasoline fueled vehicles". The fact is that diesel are inherently dirtier in NOx emissions which cause them to be classified higher than dirtier gasoline vehicles with more total pollution per mile.

BTW, if you really wanted the cleanest car out there you should have purchased the Civic CNG.

 

<div class='quotetop'>QUOTE(jhinton @ Aug 6 2007, 04:26 PM) [snapback]491472[/snapback]</div>

Isn't the 2008 EPA estimate on a 2003 Jetta Tdi 35 city 44 hwy combined 38 according to fueleconomy.gov? I know...nitpicking...

 

<div class='quotetop'>QUOTE(Alexstarfire @ Aug 7 2007, 11:29 AM) [snapback]491865[/snapback]</div>

Sorry for the typo, that should be CO, Carbon Monoxide, the nice deadly gas that you can buy detectors for at your local store so you don't die in the middle of the night. Also the gas that kills you if you decide to kill yourself by running your car in a enclosed space.

However, I won't argue that the Civic Hybrid puts out half the pollution of the TDI. Of course the TDI first came on the market in 1993 and was used unchanged until 2003. It also has no pollution controls. The new 2008's with exhaust aftertreatments for NOx and particulate filters are a quantum leap forward in emissions made possible by finally having decent fuel in North America.


<div class='quotetop'>QUOTE(kettledrum @ Aug 7 2007, 11:58 AM) [snapback]491882[/snapback]</div>

Yes, for the 2003 VW Jetta TDI SEDAN with 1.9L and 5 speed it is 35/38/44. I have the 2003 VW Jetta WAGON with 1.9L and the 5 speed with is 35/39/45 as stated earlier. I actually get the previous standard's numbers which are: 42/45/50. I find the new 2008 standard to be VERY low for my TDI. It is right on in my experience for the Prius.

 

<div class='quotetop'>QUOTE(jhinton @ Aug 7 2007, 10:53 AM) [snapback]491879[/snapback]</div>

I like the reasoning the jhinton is going for as it begins to allow us to make a better 'apples to apples' comparison between TDI diesels and hybrids as to where the emissions are actually strong or weak between either design. (What bugs me more than comparisons between TDIs and Hybrids are the tiered emission standards that keep many trucks and SUVs on the road as the polluters they are without the appropriate tax repercussions owners of said vehicles should be paying.)

That said, I do think that while the Prius is said to be an "SULEV" vehicle, the 2006 Prius model in California actually qualifies for the more stringent AT PZEV (Advanced Technology Partial Zero Emission Vehicle) standard. The only standard higher are Zero Emission Vehicles.

The California Vehicle Emission Ratings, from better to best are:
LEV---> ULEV---> SULEV---> PZEV-> ATPZEV-> -->ZEV

Currently, Volkswagen has a 2.5L inline 5 ICE New Beetle, Jetta and Golf/Rabbit that qualifies for PZEV standards. While you won't get the mileage a TDI can, there are greener options in the VW family, at least as far as emission ratings go, than the TDI's attempt to qualify for SULEV standards. But as jhinton said, some of the TDIs emission categories are very impressive--and perhaps it is a debate of "pick your poison"--but those particulate emissions are still a big distraction to TDI technology to being more of a "green" contender. Now maybe if you had a hybrid diesel solution, I'm sure you may see a stronger fight to the Prius from the VW camp. . .

 

BTW, if you really wanted the cleanest car out there you should have purchased the Civic CNG.
[/quote]


Agreed, but one should also consider the damage and longevity issues that surround a vehicle running true gasses (Propane, Nat. Gas, etc.). Even pure alcohol has this issue which is why they mix it with some gasoline for vehicle use.

Fleet vehicles running Propane aren't usually much good after around 100,000 miles and require rebuilding of the ICE.

 

This thread took off, as I figured it would... I won't add to the debate, but I'll answer the question about my avatar:

Yes, it's a photo of my car, but the plate is photoshopped in. I only wish they'd either allow the hash character, or 8 digits (in which case I'd use 0xFF0000). Since I can't do that, I think people might be even less inclined to "get it" if my plate said "FF0000" since most people wouldn't get it anyway... but maybe that's more than enough reason to go ahead and order that plate.

 

<div class='quotetop'>QUOTE(quixotequest @ Aug 7 2007, 12:19 PM) [snapback]491896[/snapback]</div>

The 2008 VW TDI will meet PZEV levels for particulate emissions. I have said this many times but I will repeat it. THE PARTICULATE ISSUE IS SOLVED FOR DIESELS! Particulate filters take care of this problem. Diesels will actually have lower particulate emissions than gasoline cars because gasoline cars put out huge amounts of particulates. These particulates are just smaller than diesel particulates and are not measured by the EPA. Diesels naturally have low CO, HCHO, and evaporative emissions. The one remaining measured pollutant that diesel struggle with is NOx.

The 2.5L Gasoline engine is not "greener" than the TDI. Let's compare 2006, which was the last year the TDI was available.

Engine -------------------------CO---NMOG-----NOx----PM----Total (g/m)-----Standard----2008 EPA Mileage
2.5L Gas (GVWXV02.5257)--0.41--0.0033----0.000----N/A------0.4133--------T2 B2---------19/22/28
2.5L Gas (GVWXV02.5253)--1.26--0.0290----0.029----N/A------1.3034--------T2 B5---------19/22/28
1.9L TDI (6VWXV01.9238)--0.04--0.0194----0.310---0.046-----0.4154--------T2 B10--------30/33/37

So the TDI has 0.5% more total emissions than the cleanest 2.5L but gets 50% better fuel mileage. The TDI is 304% CLEANER than the standard 2.5L and gets 50% better fuel mileage. Also note that the T2 B2 2.5L was only available in CARB states. So if like me you are in a non-CARB state you had a choice of a dirty gasoline engine that the EPA gave an Air Pollution Score of 6 or a cleaner diesel that the EPA gave an air pollution score of 1. THIS IS WHY I DON"T LIKE THE EPA SCORING SYSTEM. Also note that because the TDI was 1/2 percent dirtier than it's gasoline counterpart it wasn't allowed to be sold in CARB states even though the fuel mileage is 50% better.

 

<div class='quotetop'>QUOTE(Ichabod @ Aug 7 2007, 12:39 PM) [snapback]491937[/snapback]</div>

I'm just shooting off my head without referencing a web colors chart, but is that the hex code for the color of your Prius?

 

<div class='quotetop'>QUOTE(RinMI @ Aug 7 2007, 12:56 PM) [snapback]491917[/snapback]</div>

That would be the direct opposite of all the information I found when researching converting my 1961 Buick Skylark to Propane. All the research I found said the engine running gaseous fuels had longer service life and lower maintenance costs than gasoline vehicles. This was due to reduced soot and carbon buildup in the engine and no oil contamination issues from liquid fuel wetting the cylinder walls and getting past the rings. I didn't do the conversion because of fuel availability issues in my area.

Alcohol is a completely different topic.

 

<div class='quotetop'>QUOTE(jhinton @ Aug 7 2007, 01:23 PM) [snapback]491964[/snapback]</div>

By "greener" I only meant according to the EPA Emission Rating System. But I agree, completely, that it is a flawed system. It is not hard to see how VW's TDI, because one would use less fuel for equivalent miles driven, is a better option for CARB states than the 2.5L PZEV ICE. But, there you have it. Goofy regulations.

My buddy who now works for Apple is so glad he was able to take his TDI with him when he relocated, because otherwise he wouldn't have been able to buy it in California. That's silly.

As much as I like the TDI, it's going to take more than a PZEV qualified TDI to get me to switch to a new VW now that I have my Prius. (And after my 2000 mile roadtrip of the last few days I am SO wishing I could get VW/Audi-quality seats in my Prius; and, as experienced numerous times by others before, my average MPG on the trip was only in the 45.5MPG range--not nearly as impressive as hoped--though still a lot better than our Passat. So I would love to switch back to VW if the day ever comes. But you never know what Toyota will do to their next generation of product either. . . )