Jetta TDI vs Hybrid on 1 Tank from Seattle to San Francisco

Had the Jetta TDI (Bora in EU) but when I tried the prius there was no chance for the TDI - traded it straight away.

And if I could go back I'd do it again. Good riddens, TDI.

 

What you say is perfectly correct, provided you keep the Jetta always in first gear. Which is not the real world. In fourth, fifth and sixt gear, the jetta has less tourque at the wheels than the Prius, making the prius better in the real world.

P.S. Peak torque for the Prius is 358 lb-ft.

 

For heavy sour crude, perhaps 7-10% higher GHG emissions compared to ULSD. For light sweet crude, reformulated gasolines offer a clear GHG advantage

According to page 118, there are many classes of fuel and vehicle. No clear differentiation between sweet crude and sour crude, and especially no differentiation between which catalyst material is used in the refinery hydrotreater, fluidic catalytic converter, isomerization unit, or catalytic reformer, which to me is a *glaring* omission.

The pollutants I worry most about, as they DIRECTLY impact human health, are VOC's, CO, and NOx (Contributes to smog), and PM10 (Smog, plus breathing problems)

Even with ULSD and current EPA-certified diesel emissions controls in place, a diesel engine is clearly worse emitting for NOx and PM10. A diesel engine has naturally clear advantages when it comes to CO emissions

Again, the difference in refinery technology was only very briefly discussed in the reports you cited. When one considers that a modern oil refinery has almost a 1:1 ratio of crude to process water consumption, the necessity of catalyst bed cleaning or "blowdown," the need for extensive hydrotreating especially for sour crude sources, the overall GHG and especially smog forming potential are dramatically skewed

 

Well, this is an entertaining if silly thread. If for no other reason, I have a hard time believing that the "New" TDI and the Prius are competing for the same buyer demographic. Some time back I read that the "typical" Prius buyer was older (55), highly educated with income well above average. In fact, this particular market study indicated that the average education for the Prius buyer was far and away above any other car surveyed. I would like to think so, even if I am on the far left side of the bell curve but the rest of you Prius owners are making up for it

From casual observation, the "typical" VW owner is a much younger (20 something) male who actually thinks he is enjoying a performance car "experience" in one of those things. I sold an Acura TL to buy my Prius and I had an older Porsche 930 in the garage for quite a few years as my midlife crisis car. I have never been happier with any car than my Prius, and that German car ownership experience wears a little thin in the waiting room at the service department. Thanks for the memories As far as smarts go, I'll let you all judge for yourselves by observing the driving habits of typical VW drivers

I have no ill will toward VW, but I am certainly not in the market to trade down and I am unlikely to be persuaded by the sort of silly, dishonest "test" that they seem to find as persuasive. As my old grandfather used to say, "I was born during the night, but not last night."

At least this is better than the "Hummer is greener than Prius" nonsense, or a change of pace, anyway.

 

04+ Prius has 4.113 final gear reduction ratio. I overlooked it before. 3.91 is for the classic Prius.

 

"but i guess the kicker is simply... no matter what car we are talking about...for me its come down to one thing...its either a Prius, or its not..." !!!!!!!!!!!!!!!!

hehe... said PERFECTLY!!!!!!!!

 

Wow I never expected this would attract so much attention. Make no mistake, I think the Prius is an excellent car. I just happen to really like my car too, and sometimes feel that diesels are sometimes misunderstood by some members. I am sure most of you will feel the same way if you visit tdiclub, which is probably worse at even worse at understanding hybrids.

I will try to address all of your points in a single post so look for your name below. Longer posts were trimmed down to save space.

That is an excellent point which didn't click in my head until now. Applying a correction factor of 128/115 (approximate ratio of btu/gallon between diesel and gasoline) brings the CO2 advantage of ULSD over the 30ppm RFG down to about 4%. Yet somehow the difference looks bigger in the graphs? I am going to have to spend some time trying to figure that one out.

I don't know where 358 lb-ft comes from, everything I looked at said 295 lb-ft for MG2 and 82 lb-ft for the gas engine. I probably came across as wanting to have a torque contest between the Jetta and Prius but that was not my intention. I merely wanted to show that 295 lb-ft at 0 rpm may sound exciting, but it really is only similar to what a regular car will put to the wheels.

So the Prius will put out more torque than the Jetta when it's in higher gears. If that makes it better for you, then that is fine with me. I think by the time 4th gear is needed though, horsepower will be playing a more important role? In most situations, the Jetta TDI-CR will out-accelerate the Prius. However, in most situations, the Prius will get better fuel mileage and have lower emissions than the Jetta TDI-CR. Those in my mind are all hard to deny despite what fanboys of either car will say.

Glad we could entertain you I agree with what you're saying, though. To be honest, I wish the "which is faster" or "which gets better fuel economy" arguments would go away. In my mind it is pretty obvious save for some extreme cases. If somebody wants maximum fuel economy and low emissions, I will point them to a Prius with little hesitation.

In my case, the TDI and Prius could both be competing for me in the future. My requirements are fuel efficient hatchback with 4 doors. If VW comes to their senses and offers a TDI Rabbit, you can bet I will take it for a drive, along with a Prius and whatever else fits the criteria.

I have a feeling we will never agree on the WTT emissions. You have your experience telling you one thing, and I have my reports based on models from the DOE labs telling me something different. I can offer my reports to people and you can offer your experience to people and they can make up their own minds.

I place slightly more importance on CO2 than the rest of the emissions you mentioned. If I lived in Toronto, it may be different but in Winnipeg where I haven't yet seen smog -- you have lived here longer than me so maybe you have -- the VOC's and NOx aren't as high my the list as they may be for others. I'll agree the diesel is worse on PM10 and NOx. It does fare better in CO and VOC's though. So each engine wins and loses two.

If somebody wants the cleanest burning car, I will tell them to get an HCH or maybe a Prius. I have no delusions of a TDI being as clean as either of those. The problem is that not everybody wants a Civic or Prius. Somebody may want a Jetta Wagon or a Mercedes E-class, at which point I will tell them to get the diesel option. The benefits of lower CO2, CO, and VOC's outweigh the cons of higher NOx and PM10 in my mind.

The Prius now sits at 1326 lb-ft, 25 lb-ft more than the TDI idle estimate. I had a feeling I had not seen the end of the calculations

 

Consider the typical commute.

Encounters with any type of traffic will easily yield favor to the "full" hybrid of today.

Engine-Only diesel (especially manual transmissions) is old school, good for highway cruising and heavy-duty applications. Many years from now, diesel will find a place for some in the "series" hybrid.

Now consider this same Seattle to San Francisco drive with a 2010 Prius.

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HP = torque * RPM. No torque, no RPM.

In most situations the VW will be in the very long sixth gear (does your Jetta have the sixth?) and therefore the turbo needs to be revved-up before giving the necessary torque and therfore power to accelerate. By this time the Prius is at the horizon. I see this every time I climb the Highway Alps. In these cases, trust me (I had one) a manual TDI is not fun and exciting, but annoying and frustrating.

 

i am a pretty conservative driver. i dont hypermile (i dont because i use CC for about 98% of all driving conditions), but still get pretty good stats for mileage.

i drive conservatively mostly because my family is always with me (when driving alone, i take the Zenn) plus i want to get good mileage, but even then, i do get stuck behind people who drive much slower than i want to. recently on a trip to the Oregon Coast, got stuck behind a car hauler just south of Tillamook, Or. i was doing about 40 mph on a 55 mile single lane twisty curvy highway.

very little opportunities to pass and the curviness of the road meant if i did pass i potentially only had a small window to do so....well, after 25 minutes, i got a chance and took it.

now, you all can say anything you want about how slow a Pri is, but i passed the hauler with plenty of acceleration, i went from about 45 to 75 mph very quickly and did it with 3 people and a fully loaded car (5 day car trip/camping excursion and supplies on board!!)

so i have no complaints whatsoever, i dont want anything faster than i already have simply because i know that when needed, i have PLENTY of passing power available.

so argue numbers, ratios, etc all you want, or take it out on a lonely piece of straight country road and check it for yourself

 

If you carefully read the reports you provided, we are both right. You will note I am not disagreeing with the reports. GREET places far more emphasis on the so-called Greenhouse Gas. Actually, there are many GHG's: CO2, NMOG, methanes, etc etc

The Argonne study very clearly demonstrated the difference in smog-forming emissions of modern diesel and gasoline engines. The same study also contrasted the difference - much smaller - in GHG emissions

The state of California was a primary participant in these studies. You will note they discuss diesel emissions having "acute" toxcicity, as a direct component not only of smog - a ground level problem - but also of dioxins and furans. There is also the issue of NOx and various PM's

If the study had been weighted towards smog compounds, diesel is clearly the loser. Even the "tough" EuroIV diesel emissions standard allows upwards of 7 times the smog compound as a typical gasoline engine. Engines that in Europe meet the EuroIV need extensive retrofitting to meet the new EPA Tier 2 Bin 5 standards

Remember, that with few exceptions, the EPA Tier 2 Bin 5 requirement doesn't allow a diesel engine to emit more than a gasoline engine. In Europe, diesel engines are allowed to emit far more emissions than comparable gasoline engines

If your primary concern is GHG's, then it is best to modify a LD diesel engine by removing the DOC/DPF. A diesel engine has natural advantages with CO2 and VOC emissions. Adding DOC/DPF systems have a big impact on diesel engine fuel economy

I frequently travel to the UK, Germany, France, China, and Singapore on business. There is no way in hell I would want to replace most of our fleet here with diesel engines. A lot of folks may find this hard to believe, but in North America our air quality is pretty damn good - with room for major improvement of course

So in the final analysis, it's hard to dispute the fact a diesel engine puts out more smog forming compounds, even a modern diesel engine with emissions control. An older diesel engine is much worse at smog forming emissions. The Argonne data proved this

It's trickier to directly compare gasoline to diesel total energy investment, unless you pad the data to gasoline equivalent. In a modern oil refinery, the issue of rare earth catalyst consumption for distillate hydrotreating and extended separation appears to be mostly ignored by the studies

I'm not surprised by this. Most of the processes applied in modern oil refineries, such as those by Honeywell group UOP, are proprietary. Unless you have inside knowledge of the catalyst material used, you would have no idea. I was careful to point out in my oil refinery discussion the generic catalyst used, but could only mention "proprietary" to discuss the modern catalyst material

Regarding Winnipeg air quality, it is generally very good. Winnipeg is a windswept flatlander city, it doesn't have the same problem a city like Denver, Salt Lake City, Los Angeles, or Mexico City does.

At the same time if you are driving into Winnipeg from Headingly, Lockport, Landmark, or Steinbach, you will notice a light brown haze over the city if the air is very calm, especially on a hot summer day or a bitter cold winter day.

If you are driving in on the Trans Canada from the East, you will absolutely notice an inversion layer on a still day, by the time you get to Deacons

 

It seems that it really depends on the base crude being used for either fuel, what the WTT emissions and energy use will be. I think this area will be interesting to explore down the line. I would however like to see decent reports focus on the difference of source and then the refining process translated back to units the normal folsk can undersatdn in terms of gallons in the tank.

Just a couple of fine points here.

That is based on the new not yet available to public 09 Jetta TDi-CR and the almost end of life second gen NA Prius. We have yet to see what the Prius holds, who knows. Nor have we seen many idependant testing on the NA 09 TDi.

Also you assume that a TDi will provide more than 50% of its peak TQ at idle, which in my experience is far form the case. TDs have very little power till the turbo spools up, adn even with the new turbo technology lag is very noticeable. This is especially true from a standing start as well as cruisign and then accelarating. This gets emphasized even more with an auto/DSG box. And to be honest most folks that buy an econimical vehicle will prefer an auto for their commute (especially in large metro areas, where most of the buyers are).

And yes I have driven the new Audi, BMW, MB and Land Rover diesels, which are much more powerful than the Jetta TDi.

That echos some of my experiences with driving TDs. My biggest issue is the lack of a long TQ curve on the diesel engine. Even after the turbo spools up you need to keep upshifting too soon. With a gasser you can keep a gear so much longer, which in effect means you can normally hold a lower gear for those long uphill clombs and effectively have much more TQ and power at the wheels.

To be honest though the Prius does get a bit weak as the battery power gets low on those long mountian pass climbs.

 

I've been driving TDs from 1984 to 2005.

What amuses me is that when TDI is at it's sunset in Europe, thanks to the ever increasing price of diesel, in USA it starts kicking in now.

And what hurts most on TD is maintenance cost. I realize now how cheap is to maintain a Prius.

We have motorways, speed limits and tunnels that make the Alp crossing faster. In this scenario the car and battery does not suffer at all. But if I decide to take the scenic route up the passes, yes, the battery does suffer. But also the TD, due to the lack of air, thus the need to use more often first gear. So that is even.

 

Sorry, I forgot you were in Europe. In North America, (unfortunately) most of our vehicles are automatics. So the transmission will downshift when the driver steps on it. With the manual though, if the driver doesn't downshift, then he will not have much hope of catching the Prius. That would not be a very smart move by the driver, but it does happen. I do not have a sixth gear, but wish I did.

I have no issues with the Prius's slowness. My car is just as slow And I feel the same as you, 100 hp is all I need. But there is no doubt in my mind that the new Jetta is faster than either of our cars in most situations. I'd rather have it in a 100hp, 45mpg form but apparently VW doesn't believe most North Americans are like us.

My primary concern is GHG's, but removing the DOC or DPF is way beyond what I would want to do. The huge increase in NOx or PM isn't worth the GHG savings to me. I have no idea how much of an improvement there could be by removing them though. I am hoping you or somebody else here may have some information for me?

I spent a couple weeks last summer going through Switzerland, Germany, Austria, Hungary, Slovakia, and the Czech Republic. I had braced myself for bad air quality based on what I knew about NOx and smog, but found it shockingly good. I had seen much worse smog previously in Toronto and Montreal. I was also in Beijing in the summer of 2000 and they did have the worst air pollution I've seen. The huge number of coal plants and poor emissions standards on all vehicles there have much more to do with the air quality than the proportion of diesels in my mind. Of course, the diesels are probably running with little for emissions control and are pumping out huge amounts of NOx which isn't good for anything.

Most previews I have seen of the TDI-CR show it doing 0-60 in about 9 seconds. We will see how that pans out but it sounds believable to me.

I have some of the good new turbo diesels like the Honda i-CTDi have almost no lag. Of course, I have not driven it so can't say for sure.

The TDI-CR makes 236 lb-ft, so 100 lb-ft at idle is only 42% of peak torque. 100 lb-ft sounded reasonable to me for a barely turboed 2.0L diesel. Either way, the intention was mainly to show why the Prius isn't a rocket off the line despite the huge 295 lb-ft at 0 rpm, not to show that the Jetta wins some contrived torque contest.

 

My primary concern is smog-forming gases. Since Canadian emissions standards lag behind - far behind in some cases - American emissions standards, there is a clear need for Canada to adopt minimum EPA Federal standards. Ideally, Ontario would be treated like California, and would adopt CARB emissions standards

Remember that one could easily buy a new small car as late as 1990 that burned regular leaded gasoline in Canada. I have a 1984 Ford F-150 at my hobby farm that has "Non Catalyst" on the emissions decal.

Assembled in Oakville, that truck had a factory EGR block-off plate on the manifold, no AIR pump, no catalyst, and a wide fuel fill to accept leaded gasoline. Some Honda's sold here even in the late 1980's still ran on leaded gasoline, no catalytic converter

I have no problem with an annual I/M program for light duty vehicles. I also have no problem with Canada adopting US Federal emissions, preferably CARB emissions, and getting MMT out of unleaded gasoline

There have been reports that specifically address air quality and diesel exhaust

http://www.toronto.ca/health/pdf/de_technical_appendix.pdf

ANother issue being industrial emissions, which are at levels many times higher than allowed under US EPA standards. Of course, it would cost billions to retrofit the industrial plants to meet minimum American emission standards

I find traveling to the EU, there is a noticeable difference in air quality. About a year ago I moved out of Winnipeg - which has very good air quality for a city that size - into a smaller community, and have enjoyed much better air quality as a result. So I find the difference very immediate

Diesel engines fitted with all the latest emissions controls appear to suffer large fuel economy losses, upwards of 20%. We did have some Dodge Ram Cummins trolls awhile back bragging how they had removed their emissions, and turned their trucks into black smoke belching monsters with 20 MPG highway. How very impressive.

I'm not knocking you personally, but on average I find diesel fanboys appear to ignore the toxic emissions of diesel engines. A lot of them try to argue that the black smoke is harmless. In that case, I say run a pipe from the exhaust into their bedroom, after all it's "harmless"

However, I have heard enough annecdotal reports from RV owners who compare the early 1990 Dodge Ram Cummins to the new ones. Overall, the new trucks offer 20-30% lower fuel economy than the old ones

If you really want to experience crap air quality, and not have to travel +12 hours in a plane to do so, consider a trip to Mexico City. Nasty. If you like chemistry, and I do, you may find this interesting

Air pollution in Mexico City, smog, health effects, fossile fuels

Emissions controls do work. A lot of folks consider Los Angeles air quality bad, and it is compared to Winnipeg. However, it has really improved from the early 1970's.

Historic Ozone Air Quality Trends

In the end, what do we do? We use the cleanest vehicle possible, use mass transit, and make proper choices regarding homes, appliances, etc

 

While I fully admit I skimmed some of the posts in this thread and don't intend to fuel a flame war, I could not resist a comment.

My wife and I are fortunate to own several nice rides (see my signature) one of which is a C6 vette convertible. When shopping for the Prius I did consider the Jetta TDI and waiting, but was dissappointed with the fuel economy numbers of the car when they were revised down from initial reports. Yes, I drove a Jetta (my neighbor has a pretty new one, admittedly not a TDI) and while I enjoyed the car it did not strike me as having any kind of significant advantages over the Prius other than perhaps the handling. Oh and maybe the ability to get a factory sunroof.

I would argue that the technology and engineering that went into our C6 is on par with that of the Prius, but the focus was for an entirely different venue. That said we enjoy them both for different reasons. The Prius is my daily driver and I love it. I did not buy the Prius for performance. I wanted the most fuel-efficient car I could get. I love the fuel economy of the Prius, the technology and the relative comfort compared to other cars in this segment. I do think it is a "fun to drive" car and just as much fun as the vette and in some ways more so, but for different reasons. When I want raw performance, out come the toys - most notably the vette. The vette is not my daily driver and I love it. I love the exillerating acceleration, the incredible handling and the technology under the hood. I also love the 27-28mpg I can get when I keep my foot out of the accelerator.

So I guess it comes down to what is your primary goal you're trying to accomplish with the car. If it's the number one rated car for fuel economy and dependability in a daily driver that can also function as a family sedan - to me the Prius is a no brainer assuming you are not being gouged at the dealer. (We drove lots of cars, ran the numbers with multiple spreadsheets, hybrid, non-hybrid, etc.) If it is anything other than this, then you have a ton of choices even at the 22K-25K price range both cars list in. I have to question the value of choosing diesel over even conventional gas engines given emmissions and the higher cost of fuel for what becomes in my mind more of a modest gain in fuel economy compared to its 4 cylinder siblings and competitors.

Just my 2 cents. Bottom-line, it's all relative.

 

This is exactly the way I feel as well. I've been fortunate to either own or have owned or had access to as a company car (hey, I'm in the Internet business) some of the most desirable cars out there, up to about the $135k range. The Prius is about as fun, and in most cases more as any car I've ever driven.... just in a different way. Okay, the '03 911 twin turbo was pretty damn fun (although tiptronic was lame)... but the damn thing was frequentyly in the shop.... and the SL500 was garbage as well. I've never seen a car fall apart in front of my eyes as I did the SL500.

My business partner has a Bentley GT and a S550. Both expensive cars luxory. When we go to lunch, I much rather take my Prius. I don't know what it is about the Prius but you build a bond more than with most other cars. It's hard to explain.

 

Here is my 2 cents worth.

Volkswagen makes a great vehicle as does Toyota. We owned a 2006 Jetta TDI prior to our new 2008 Prius Touring pkg 6.

The Jetta was fun to drive, very well built and very economical*. We traded the Jetta off for the Prius. Our dealer actually paid off our loan and gave us incentives amounting to our purchase being over $1200 under Toyota sticker to us.

The reasons we are no longer driving the Jetta TDI.

1. VW Dealer Rape case. (you get raped when you have to pay for service $$$$$) VW is extremely proud of service and parts (PLUS DIESELS cost more)

2. Diesel fuel pumps are too limited in our area.

3. Great deal from Toyota dealer. Bought in March before increases.

***BONUS***
Insurance is cheaper on a 2008 Prius than a 2006 VW Jetta TDI.


A couple last points:

ALL auto manufacturers today make "quality" autos. Some make "High Quality".

You can get a "LEMON" from any auto maker. You see the highest quality car makers in the world recalling cars every day.

 

My point was that you are comparing a TDi model that is not yet in public hands with an almost end of life Prius I would love to see the verified performance and mileage of the new TDi, but I would prefer them to test a DSG which is much more applicable for the average commuter.

I think we both would agree that neither car is fast, nor is it the intended purpose of these vehicles. My point is that evry new generation they claim that there is virtually no turbo lag However there will always be turbo lag, especially on high output TDs. SImply put a A turbo will alwasy need time to spool up and the more boost it needs to make the longer it takes and bigger the effect feels.

I still think 100 lb-ft is highly unrealistic for a 2.0 TD at idle. It actually will give worse TQ than a non Turbo diesel at idle as the compression is lower and the airflow is resticted more by the Turbo system (which isn't doing anything for it at idle). The turbo needs to spool up and only start doign somethign useful around 1200RPM on these types of engines, normally they get close to peak TQ around 1500RPM, but there is a world of difference between 1000 and 1500 RPM (which can be very frustrating when driving in the city).

The Prius electric motor delivers a constant 295lbft from 0-30MPH, that excludes the addition of the gas engine with relevant TQ multiplaction due to the final drive and panetary gear system. After that the TQ on the electric motor gradualy decreases (but it is still in it's "1st gear" so to say). No gear shifts needed so just a continious flow of power. It is hardly a very fast vehicle, but much faster than it feels or a lot of people think.

 

I did a small research for someone else, I will share it with you:

Code:

                                   Prius 1.6 FSI TDI 110 TDI 140
Acceleration (seconds) 0-62 mph    11,9   13,6    12,1      9,6
400 m from standstill              18,4   19,1    18,4     17
1 km from standstill               33,6   35,2    33,6     31,2  
Pick-up (seconds) 45-75 mph        10,1   29,8    15,6     13,9
1 km from 45 mph                   28,5   35,7    38,8     29,9

The pick-up test is done in top gear, to determine the time needed for the car to regain speed.

You can see from the test above that if you want to beat the prius you need at least 140 diesel horses. Twice as much as our hybrid horses....