VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanics

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

<div class='quotetop'>QUOTE(john1701a\";p=\"61784)</div>

John and everyone: There is some misconception about the use of biodiesel in very cold weather. A lot depends on the source crop from which the biodiesel is made; it can be produced from a very wide variety of crops. The most common source crop is soy. In winter, my partner adds a few gallons of regular diesel to his tank if the temp is predicted to go below 25F, and that is sufficient to keep the fuel from jelling. He has tested his fuel, which he makes himself, and it's remained un-jelled as low as 25 degrees F. Folks living in Minnesota will need to add some conventional diesel in winter.
Cost is an issue, but the government is producing legislation that will offer some tax relief, at least to fleet users. For every percent of bio diesel added to a mix, there is a one cent reduction in the tax.. So, a mix of 20% bio diesel/80% conventional diesel, qualifies for a 20 cent reduction in the fuel tax. Bio diesel can be mixed in any ratio with petro diesel with no modifications whatsoever to the engine.
The reduction in pollutants is remarkable and bio-diesel does not introduce new CO2 into the atmosphere (because it releases only the CO2 which the plant contained originally), which is a major selling point.
If you compare a Jetta TDI running on biodiesel against a Prius, you get a remarkably close comparison, with, I think, an advantage to the biodiesel fuel source as it is completely renewable.
Bob

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

<div class='quotetop'>QUOTE(jayman\";p=\"62552)</div>

I don't mess with buggy, cheap consumer gadgets, almost all of my work is in industrial process control with embedded RTOS. I also don't care about "ease of 3rd party integration" as the tools I work with provide enough functionality.

You pick a proven communication protocol, such as DeviceNet, ControlNet, Foundation FieldBus, or Industrial Ethernet, and make sure the device in the field (Sensor like position, RTD, pressure, ORP, etc) is reliable, with plenty of early warning before catastrophic failure.

I want rock-solid reliability. If you're messing with sodium hydroxide, chlorine, or other nasty things, the last thing you want to deal with is some deranged OS running wild. I want a system that will do watchdog checks and provide nice Hot Restart groups if something DOES abend.

According to Consumer Reports, the BMW systems, in particular the i-drive, have much less than stellar reliability. I find it quite odd that a luxury mark like Lexus can package all the latest features into a very reliable car, but the German companies (BMW, DC, VW, etc) cannot.

I personally don't trust "ease of 3rd party integration." The first problem with CMM +5 is the huge cost - and time - involved in all that prototyping and testing, to ensure delivery of an absolutely reliable software product.

It stands to reason that frequent "updates" have not been thoroughly tested and you will encounter field problems that quick iteration testing failed to uncover.

If it's a car, it rolls to a stop and you call Roadside Assistance. If it's a chlorine cell, you kill a lot of innocent folks.

It's a very sobering reminder to me of reliability issues when I check up on software packages that I wrote in the late 80's or early 90's that have run 24/7 without fail, then go back to my home and encounter "PFN_LIST_CORRUPT" on Windows XP Pro.[/b][/quote]

Not to get religious on your butt, but.....

Most of the problems with iDrive are due to implementation, not due to the fact that it's written with Java. Any system that has you drill down 3 menus to change fan speed has issues. Exposing those functions at a higher level to the user is something BMW should be concerned with, not whether it's written in C or C++.

I've personally seen realtime java systems survive someone yanking a powercord (instant failover) and whatever else you can throw at them. I've seen JINI stubs written in less than 30K and shoved onto a chip (complete with a bluetooth stack). Java, really, can do anything C or C++ can do these days.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

> my partner adds a few gallons of regular diesel to his tank if the temp is predicted to go below 25F, and that is sufficient to keep the fuel from jelling.

A few gallons translates to what percentage? 20% would be about 2.5 gallons for a typical car, leaving about 8.5 gallons for the other if starting with an empty tank. So I guess the real question could be "down to what temperature?" before you have a concern.


> Cost is an issue

Yup. And with the tax relief, you are lucky to break even... since local grown fuel is less efficient than the dino stuff.


> an advantage to the biodiesel fuel source as it is completely renewable.

That isn't really relevant, since FFV is a well established technology at this point too.


In other words, we have to clearly define what the goals are. Which gets the greatest priority, reducing emissions or increasing efficiency.

Then ask yourself what level would you find acceptable... SULEV & 50 MPG?

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

By the way, Minnesota is working on a mandate to make B2 required.

That means all diesel sold would be 2% biodiesel, which is a far cry from 20%... or even the 10% ethanol that has been required in all gasoline since 1997.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

<div class='quotetop'>QUOTE(Jonnycat26\";p=\"62634)</div>

In the industrial automation world, you don't encounter JINI. Many hazardous automation scenarios require CMM Level 4 or CMM Level 5, and I'm not aware of any Java embedded systems capable of reaching Level 4 or Level 5.

To achieve Level 4 or Level 5 involves far more than hot failover upon power loss. Among other things, exception throws/catches are very explicit and you have to perform confidence-checks on input data. In a critical process environment, you can't guess and you can't depend on general exception throws/catches to save your a**.

The Bluetooth stack you're referring to is a wireless communications protocol. I'm not talking about wireless comm, which BTW is notoriously unreliable.

I'm talking about triple-redundant ORP (Oxidation Reduction Potential) sensors and RTD (Resistance Temperature Detector) sensors in a hazardous environment, where a failure could result in an explosion and the release of toxic materials into the environment. Those toxic materials could kill many, as the Bhoupal, India Union Carbide plant proved to the entire world.

In that scenario, a proven embedded RTOS from Wind River (VxWorks), QNX (Neutrino), or Sun Microsystems (Chorus) is used to control the device in question. The master device is also configured as a backup LAS (Link Active Scheduler) to take control of the immediate process if communication is lost with the control room.

Otherwise, if you sever the communication link to the control room (It happens, one misplaced drill will do it), the sensors and control devices (Valves, pumps, etc) go dead. In a chemical plant, that is a catastrophe. In a petroleum plant, losing control of a fractionator or distilator is also a catastrophe, as it will usually explode.

Getting back to the original thread, my neighbor with his BMW i-drive system is very unimpressed, and not just because of the complexity of the menu's (The UI or User Interface). His i-drive is buggy and it's ALWAYS BROKEN.

He's always getting error messages, at least once a month the stupid thing is in the shop for tweaking and "updates." He expected much more from a car that set him back +$75,000 CDN.

It doesn't help one bit that the service personnel, with odd names like Dieter and Guenther, are VERY condescending to him and have now become outright rude. How DARE he complain about obviously "superior" Siemens technology!

The best thing about his misadventures and escapades with that BMW? I think he's really, really serious about getting a Prius! Since he spends enough time in mine when I give him a ride to work, he's grown attached to my Prius and is comfortable with it.

Compared to the i-drive, he could adjust the HVAC himself, without having to read an instruction manual the thickness of War And Peace. Although my Prius did croak once, this pales in comparison to how unreliable his BMW is.

He got his BMW as a Status Symbol, and he is the first to admit that my Prius, at 1/2 the cost, is a far more visible Status Symbol.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

<div class='quotetop'>QUOTE(jayman\";p=\"62731)</div>

In the industrial automation world, you don't encounter JINI. Many hazardous automation scenarios require CMM Level 4 or CMM Level 5, and I'm not aware of any Java embedded systems capable of reaching Level 4 or Level 5.

To achieve Level 4 or Level 5 involves far more than hot failover upon power loss. Among other things, exception throws/catches are very explicit and you have to perform confidence-checks on input data. In a critical process environment, you can't guess and you can't depend on general exception throws/catches to save your a**.

The Bluetooth stack you're referring to is a wireless communications protocol. I'm not talking about wireless comm, which BTW is notoriously unreliable.

I'm talking about triple-redundant ORP (Oxidation Reduction Potential) sensors and RTD (Resistance Temperature Detector) sensors in a hazardous environment, where a failure could result in an explosion and the release of toxic materials into the environment. Those toxic materials could kill many, as the Bhoupal, India Union Carbide plant proved to the entire world.

In that scenario, a proven embedded RTOS from Wind River (VxWorks), QNX (Neutrino), or Sun Microsystems (Chorus) is used to control the device in question. The master device is also configured as a backup LAS (Link Active Scheduler) to take control of the immediate process if communication is lost with the control room.

Otherwise, if you sever the communication link to the control room (It happens, one misplaced drill will do it), the sensors and control devices (Valves, pumps, etc) go dead. In a chemical plant, that is a catastrophe. In a petroleum plant, losing control of a fractionator or distilator is also a catastrophe, as it will usually explode.

Getting back to the original thread, my neighbor with his BMW i-drive system is very unimpressed, and not just because of the complexity of the menu's (The UI or User Interface). His i-drive is buggy and it's ALWAYS BROKEN.

He's always getting error messages, at least once a month the stupid thing is in the shop for tweaking and "updates." He expected much more from a car that set him back +$75,000 CDN.

It doesn't help one bit that the service personnel, with odd names like Dieter and Guenther, are VERY condescending to him and have now become outright rude. How DARE he complain about obviously "superior" Siemens technology!

The best thing about his misadventures and escapades with that BMW? I think he's really, really serious about getting a Prius! Since he spends enough time in mine when I give him a ride to work, he's grown attached to my Prius and is comfortable with it.

Compared to the i-drive, he could adjust the HVAC himself, without having to read an instruction manual the thickness of War And Peace. Although my Prius did croak once, this pales in comparison to how unreliable his BMW is.

He got his BMW as a Status Symbol, and he is the first to admit that my Prius, at 1/2 the cost, is a far more visible Status Symbol.[/b][/quote]

As far as I know, it's only reached CMM 3. So you may have me there. But I seem to recall at the last presentation I went to on this that they were aiming for the highest levels, so who knows.


Having come from a German car to a Prius, I can say that I find myself not at all missing the repair bills, but totally missing the driving feel.

 

<div class='quotetop'>QUOTE(john1701a\";p=\"62641)</div>

Using biodiesel eliminates the two barriers that diesels have trouble overcoming. One is the particulates, and the other is the sulphur content of the fuel. Eliminating the sulphur without putting the fuel through the desulphurization process now required, eleminates the issue of stripping the fuel of it's lubricating properties - the fuel pumps live happeir lives. The elimination of sulphur makes it possible to use a catalytic convertor to deal with the NOx emissions. With Biodiesel, you can have your SULEV rating, and 50 mpg to boot. I do agree though, that the percentage needs to be higher than 2%. 20% has long been considered the minimum amount of biofuel required to make a difference in pump fuel.

I've run my truck on homebrew B100 without any issues.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

<div class='quotetop'>QUOTE(Jonnycat26\";p=\"62742)</div>

Once I receive absolute proof that JINI and the overall JavaOS environment is suitable - safe - for a hazardous environment, sure I'll use it. It would make my job a lot easier. Until that happens I have to stay with proven RTOS's, proven BSP's, and proven libraries.

I guess I've outgrown the "driving feel" aspect, if I ever did have it. To me, a car is just one more appliance.

 

<div class='quotetop'>QUOTE(Wolfman\";p=\"62750)</div>

I think the biodiesel issue is really overblown here in North America. Europeans appear to have good luck with Rapeseed and a suitable cosolvent, such as methyl ester.

I was watching BBC World's driver show Top Gear a couple of years back. They ran a Volvo diesel car on a homebrew of used cooking oil and a good cosolvent, I think it was turp.

For some reason, here in North America we prefer high sulfur diesel fuel, which really adds to the particulate problem. Euro market diesels must use ultra-low sulfur fuel to meet Euro3 emissions requirements.

It's not impossible to design a direct injection system, such as the Pumpe Duse by VW, that will live a long and happy life on no sulfur or on biodiesel. Old habits die hard I guess. Look at the resistance to EFI when it first came out.

In a large-scale processing scheme, a suitable cosolvent like methyl ester is probably easier to blend and achieve consistent quality. Even if it "only" reduces our foreign oil dependance by 15%, we should do it. Not to mention we can take current "waste" crops, so the net carbon stays the same.

For extreme cold climates, "regular" diesel fuel, or "#2," is unsuitable below approximately +10 F. It will gel and turn completely solid by -25 F.

So you still have to blend for cold climates anyway, whether you use "real" diesel or biodiesel.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

Everyone who questions the ability of a diesel to be clean should mosey on to the "other cars" forum and check out the post on the Mercury Meta concept. In a nutshel, it's a hybrid which uses a diesel V6 for it's ICE. It's PZEV rated, which if it makes production would be a first for a diesel.

A clean diesel is definetly doable.

 

PZEV rated??

when?

in park?

 

<div class='quotetop'>QUOTE(DaveinOlyWA\";p=\"62817)</div>

Ah, an open mind. Please do refer to the posting and read the article. It's doable.

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

There is no reason why a LD or for that matter a HD diesel motor cannot be made to achieve low emissions. Although we - specifically the United States - pioneered emissions controls, the Europeans have in some matters surpassed us.

As an example, the Europeans got most of the sulfur out of diesel fuel. Canada has had low-sulfur diesel for a long time, but the European diesel fuel is much cleaner again.

That's easier to achieve with "sweet" crude. With "sour" crude, which is most of that wonderful cheap mideast oil, you need a lot of extra refining steps to remove the sulfur. That's expensive.

You can design a diesel motor with advanced electronics and with very high pressure direct injection. The PD "Pumpe Duse" design you see on small new VW motors is also used on large HD diesel motors, such as the electronic Cummins ISX and the European MAN trucks.

You design the motor much "tighter" so a lot of the blowby and particulates are no longer generated. A water-cooled EGR is used to reduce NOx. Tack on a catalytic convertor and, thanks to no sulfur in the fuel, the motor is very clean.

The only problem is that HD diesel oils had to be reformulated to deal with the much increased soot loading of the oil. When American truck motors, such as Cat and Cummins, first redesigned to reduce blowby and particulates, the oil couldn't cope with the heavy soot loads and motors had early failures. That's long behind us.

 

My impression, from several different news articles, is that the cleaner fuel is the key to allowing clean diesels in the U.S.

Also that there is some legislation coming up that would require that diesel fuel sold in the U.S. was as clean (or close to as clean) as European diesel fuel.

Is this true?
[hr:97d8a28956]
Speaking for myself, if someone can come up with a clean diesel hybrid, I'm all for it. Greater gas mileage, low emissions. I think that's a win-win situation.

(Plus, I remember some thread around here pointing out that Toyota had come up with some extremely efficient diesel engine, for an industrial engine competition. So I'd suspect that there are engineers at Toyota thinking about diesel hybrids -- and probably doing more than thinking.)

 

Which month edition was this popular mechanics issue? i looked for the article in the pop mechanic magazines in the store but didn't find it

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

To answer a question, 2006 is the year (June actually) when Ultra Low Sulfur Diesel (ULSD) (15ppm!!) will be required for 'most' diesel fuel offered at pumps. A good study on how this may be accomplished and risks to supply/demand is located here:
EIA Special Report
It's obvious that this is GOING to happen, the question is how much this administration is going to slow it down. :roll:
I would offer a guess as to why N.America has such high sulfur content.....we are CHEAP!!! Americans are unwilling to pay high prices at the pump.
Now the revealing part....I have done quite a bit of research into which vehicle is better for the environment (hybrid or biodiesel) and it's extremely hard to find this info. Bio is not yet ASTM certified, but is quite safe when bought from a real supplier and from what I've been told by more than one person here in Seattle - MORE efficient (1-2mpg typ) than straight diesel.
Info Running straight diesel in a VW TDI, things are probably not as good as a hybrid. But running B100 (or even B50 - 50% Bio) is a different story entirely. As was mentioned in other posts, greenhouse gas emissions are basically nil with B100. Gas hybrids can't even come close to that.
Here are a few sites containing Biodiesel fuel information:
http://www.tacomabiodiesel.org/
http://www.biodiesel.org/
http://tdiclub.com/TDIFAQ/TDiFAQ-5.html

The VW TDI may be a little more expensive to operate, but more fun to drive and no fossil fuel use in the Summer at least. I plan to get one in the next couple weeks.
The paradigm shift I made was to feel good knowing I am helping to build up an industry that can make a massive difference in greehouse gas emissions......and it's already here.. Well, sort of. I realize Biodiesel is still not available in most of the US. It's coming. Here is a primary website we use in the Puget Sound to tell us where, which also has links to national map tool:
http://www.fuelwerks.com/

I do applaud everyone buying hybrids as well. Together we will all make a difference.. :mrgreen:

 

Re: VW Jetta GL TDI vs. Toyota Prius in new Popular Mechanic

An important point to keep in mind is that a lot of the initial reluctance to removing sulfur from diesel fuel in North America had to do with the perceived fear of early rotary injector pump failures.

Sulfur - in low amounts say 100ppm - acts as a lubricant within the rotary pump unit. Reduce sulfur down to 25ppm or especially below 5ppm and the pump will experience early failure unless you use supplemental additives.

The only problem with the industry claiming sulfur is a "necessary" lubricant is that, thanks to modern emissions requirements, no major manufacturer has used the old-fashioned rotary injection system in a decade. You still find those systems in agriculture (Tractors) and in many older motors, but it can't burn clean enough to meet modern emissions.

Here's a twist: the rotary injector pumps made by Bosch were redesigned to live with no sulfur in diesel a LONG time ago. The units made by Stanadyne were not.

What's really ironic is that the modern unit pump injector is also made primarily by Bosch. So it will be quite happy running on diesel <5ppm sulfur.

True the older transport trucks will experience rotary injection pump failures. When you consider how much more emissions, especially particulates, they put out, it's not a bad thing to get them off the road.

 

I believe I'd heard about the low greenhouse gas emissions of this sort of diesel as well.

However, wasn't the downside that there is a higher percentage of particulate emissions (or at least a type of particulate emissions) with diesel, compared with standard petrol? I thought that's what the low-sulfer diesel was primarily supposed to correct.

PS Thanks for all the informed information being posted about this -- as you can tell, I'm not a diesel-knowledgable person!

 

If diesel has "low greenhouse gas emissions" it would be solely due to the higher thermal efficiency of the diesel cycle.

The real problem has always been NOx emissions. In a gasoline car, a catalytic converter can remove most of these, but with high-sulpher fuel you can't effectively have a catalytic converter (not and have it last very long unless it's really expensive). And diesels produce inherently more NOx than gasoline engines due to the higher combustion temperature and frequent lean burning.

Carcinogenic particulates are another big problem. Those can be filtered, but currently they aren't required to be in the US, so they aren't.

Oh, and unburned hydrocarbons can be a problem unless carefully managed, because the only way to change a diesel's power output is dumping in more fuel (there's no throttle). Eventually the engine spools up to where it can actually burn all that fuel, but in the mean time it spews it.

Again, all of these problems are at least theoretically fixable. They just aren't typically fixed.

 

SO what edition was this popular mechanics?