Diesel car considerations

[DaveStPaul]

Do you drive a diesel car? Or did you consider one and decide against it?

We've been overseas for almost four years, but are getting transferred back to the US in July. While we've been away the price of gas has gone up so much it's made us reconsider what kind of car we'll get.

A big thing you notice when comparing gas mileage is how well cars with diesel engines perform. And the financial side of this consideration is easy: does the money you save in better mileage offset the higher price of the fuel and the car?

What I'd like to hear from anyone who can help, though, is about the other issues: diesels run dirtier, they run noisier, the filling stations are fewer and farther between, they freeze up in cold weather. (Since we're moving to Minnesota, that last point is especially important.)

I can find video presentations on YouTube by VW saying, "You might have heard these bad things about diesels, but with our new technology there's no difference between our diesel and a standard engine," etc. But that's them talking. I've also been reading analysis on edmunds.com, etc. But I'd like to know what any of you have found.

Thanks very much, I appreciate any help you can offer.

[goldy_331]

Re: Diesel car considerations

Do you drive a diesel car? Or did you consider one and decide against it?

We've been overseas for almost four years, but are getting transferred back to the US in July. While we've been away the price of gas has gone up so much it's made us reconsider what kind of car we'll get.

A big thing you notice when comparing gas mileage is how well cars with diesel engines perform. And the financial side of this consideration is easy: does the money you save in better mileage offset the higher price of the fuel and the car?

What I'd like to hear from anyone who can help, though, is about the other issues: diesels run dirtier, they run noisier, the filling stations are fewer and farther between, they freeze up in cold weather. (Since we're moving to Minnesota, that last point is especially important.)

I can find video presentations on YouTube by VW saying, "You might have heard these bad things about diesels, but with our new technology there's no difference between our diesel and a standard engine," etc. But that's them talking. I've also been reading analysis on edmunds.com, etc. But I'd like to know what any of you have found.

Thanks very much, I appreciate any help you can offer.

bb_dl may want to chime in here...

[ScottM]

Re: Diesel car considerations

I recently bought an Audi A3, and gave serious thought to the diesel TDI offering. Ultimately, I opted for a gasoline TFSI since VW-Audi doesn't mate the TDI with quattro in the US. Edmunds.com has lot of current, good information about modern diesels, hybrids, etc.

The Europeans, BMW, VW, etc. have really upped their games with regard to diesels, and a lot of the good press seems true. They don't smell bad, are more reliable, deliver a good deal of power, etc. (Audi's TDI has won the 24 Hours @ Le Mans over the past few years.) There was also an article about diesel offers in the Wall Street Journal within the past 2-3 weeks. You can probably find it online. I think your concern about northern winters and diesels is valid, but I know Audi has cold weather options for diesels, such as "preheating", etc.

[unh_hockey]

Re: Diesel car considerations

They get better gas mileage, but the fuel costs slightly more. If I had to guess, I’d say that it would pay off in fuel costs especially when prices are higher for all petrol products. As for the freezing problem, I think they blend based on locality so if you are in a colder spot of the country, they should have a different procedure/ additives so the fuel will operate. Cold days in NH, you can see Diesel’s on the side of the road so clearly this problem does exist.

VW has a good Diesel in the US, and I know several other good brands have solid Diesels overseas. Unfortunately they don’t pass our standards so we may never see them. My wish list is the Subaru Legacy which can get 40-50 highway, and has a 700-800 mile range. I hear the VW even has a turbo, but they won’t ever be as fast off the line as a petrol turbo..not that is matters to most people.

A diesel is next up on my car buying list once the WRX has run its course. Which one..who knows. Lets hope the market opens up a little bit in the US in the next 5-10 years though…

Best of luck.

[unh_hockey]

Re: Diesel car considerations

Because now you got me curious:

http://legacygt.com/forums/showthrea...ca-90248.html?

Basically its arugable you save much with Diesel given that its more expensive. The cost savings was 30 % a number of years ago, and is something like 17 % now. So the difference has steadily declined.

(laughable inside joke for anyone who read my previous threads: the first response to the thread talked about the inefficiency of corn ethanol. )

[amherstblackbear]

Re: Diesel car considerations

They get better gas mileage, but the fuel costs slightly more. If I had to guess, I’d say that it would pay off in fuel costs especially when prices are higher for all petrol products. As for the freezing problem, I think they blend based on locality so if you are in a colder spot of the country, they should have a different procedure/ additives so the fuel will operate. Cold days in NH, you can see Diesel’s on the side of the road so clearly this problem does exist.

VW has a good Diesel in the US, and I know several other good brands have solid Diesels overseas. Unfortunately they don’t pass our standards so we may never see them. My wish list is the Subaru Legacy which can get 40-50 highway, and has a 700-800 mile range. I hear the VW even has a turbo, but they won’t ever be as fast off the line as a petrol turbo..not that is matters to most people.

A diesel is next up on my car buying list once the WRX has run its course. Which one..who knows. Lets hope the market opens up a little bit in the US in the next 5-10 years though…

Best of luck.

I know at one point VW had to stop selling diesels in Mass. because of emissions requirements. But if you search dealers, they have turbo-diesels in inventory today.

So there must be something else going on. Are the U.S. diesels "special?" That might explain why other manufacturers dont bring them over. VW has enough history, and their TDI brand has enough recognition that it's worthwhile for them to make separate diesels for the U.S. market -- while others who would be starting from scratch (Subie?) aren't willing to make the leap...

[goldy_331]

Re: Diesel car considerations

Because now you got me curious:

http://legacygt.com/forums/showthrea...ca-90248.html?

Basically its arugable you save much with Diesel given that its more expensive. The cost savings was 30 % a number of years ago, and is something like 17 % now. So the difference has steadily declined.

(laughable inside joke for anyone who read my previous threads: the first response to the thread talked about the inefficiency of corn ethanol. )

But what about the inefficiency of soy diesel?

[unh_hockey]

Re: Diesel car considerations

So there must be something else going on. Are the U.S. diesels "special?" That might explain why other manufacturers dont bring them over. VW has enough history, and their TDI brand has enough recognition that it's worthwhile for them to make separate diesels for the U.S. market -- while others who would be starting from scratch (Subie?) aren't willing to make the leap...

Its probably a combination of fuel costs, regulation, and a perceived niche market which keeps most diesel’s out of the US. Subaru is already a niche market with their performance vehicles. While reliable, they do not get great gas mileage, and require high octane fuel. Throw in a niche within a niche market, and you probably have the execs at fuji heavy industries saying…no thanks.

Me and my roommate had to replace spark plugs on our respective Subaru’s. His was a late 90s RS with a 2 L engine, mine a WRX with a turbocharged 2.5 L boxer engine. My god, when you throw in a turbo, the amount of CRAP you have to get through to get to your spark plugs is ridiculous. He was finished in half the time, and I started like an hour before he did. I had to remove my air intake, secondary air pump, battery, filter all to get to a spark plug that a baby’s hands could barely reach. What’s the point of this story? Turbo charged engines need more ‘stuff’ under the hood to get too. Imagine a Diesel that needs even more ( NOx reduction, filters etc) and suddenly your packed car becomes even more packed making serviceability a nightmare. Perhaps this too is a reason diesel isn’t common here.

[alfablue]

Re: Diesel car considerations

So there must be something else going on. Are the U.S. diesels "special?" That might explain why other manufacturers dont bring them over. VW has enough history, and their TDI brand has enough recognition that it's worthwhile for them to make separate diesels for the U.S. market -- while others who would be starting from scratch (Subie?) aren't willing to make the leap...

Its probably a combination of fuel costs, regulation, and a perceived niche market which keeps most diesel’s out of the US. Subaru is already a niche market with their performance vehicles. While reliable, they do not get great gas mileage, and require high octane fuel. Throw in a niche within a niche market, and you probably have the execs at fuji heavy industries saying…no thanks.

It's all about emissions.

In the US, the rules do not distinguish what fuel is run- all cars and trucks must pass the same.

In Europe, the rules have a large difference, as well as how the standard is laid out. But the essence is that diesels are allowed to pollute more. Although, looking at the new EuroV and EuroVI rules, it appears that they realize that it was a mistake. Both have a significant reduction in diesel emissions, particularly with particulates. Based on what they look to be, I have been guessing that the A-CD class cars (Smart-Jetta) will loose diesel as an option except for the more expensive cars. Mainly due to the cost of the aftertreatment and losses of efficiency to meet the new rules. That, and diesel fuel is very close to gas fuel in Europe. Doesn't take a long trip in any major city there to see the error in biasing toward diesel.... But I've also heard that much of the soot on the Greenland ice sheet can be traced to European sources....

OTOH, the new rules in coming in the US (both EPA and CARB) appear to give diesel a slight break, in how the standard is moving from a chemical specific to a combined standard. Doubt it will bring much new here.

Still- every OEM has diesels, and if there was a market, and if they could sell it, they would. But VW, BMW, and Mercedes seem to be the only ones who think a competetive diesel is a possibility. And even then, the numbers are so small, well......

(Turbos are a problem, but that's not diesels biggest problem- there are a bunch of new turbo direct injection gas cars for sale in the US)

[bigblue_dl]

Re: Diesel car considerations

I would recommend going the diesel route. I have a diesel, and have had no problems living in the cold weather. I had to leave it in the Enterprise parking lot for a week, while I went on a business trip, it was a steady -30 that week, my truck started right up without any starting aids. I was impressed with that performance.

I can address all of your questions, but it may be a long post. I actually spend several years developing fuel ratings for diesel engines for my company, so I have the technical side covered very well.

1. Cold Weather
Cold weather is a legitimate concern when it comes to diesels, for several different reasons. First, #2 diesel fuel will gel at colder temperatures. There is a wax in diesel fuel, which helps lubricate the engine/fuel pumps/etc. and extend engine life. When the temperature gets cold, this wax separates out from the other components in the fuel and clogs up fuel filters and lines. It becomes a big mess. Luckily, in the upper midwest, we have this figured out. There is also #1 diesel that can be used (not recommended), and that is good down to something like -60. The fuel companies blend these 2 types of fuel throughout the winter to make sure that the fuel is adequate for the weather. The blending starts in about mid-October, then they step it up in December. In the depth of winter the diesel at the pumps would be good down to -40. The second concern is hard starting. Diesel engines are notoriously hard to start in the cold. This has been improved alot over the last several years, changes in fuel system design and better glow plugs have helped. You will have to "wait to start" when it gets cold, this is so the glow plugs have a chance to warm up the internal cylinder temperature. (I think any diesel you'd get would have glow plugs...there are other strategies for this, but in the automotive world I would expect glow plugs) Also, it would be best to plug in the block heater if its going to sit outside, which is a good idea for all engines, actually. It keeps the oil thinner, so you provide better lubrication for the engine.

2. "Dirty Diesels"
This is the #1 problem diesels face today, and it isn't even a problem. People that aren't familiar with the new diesel technology instantly think of those old diesels puffing out black smoke. This is not the case anymore, the EPA put an end to those diesels several years ago. New diesels run a particulate filter in the exhaust to control PM (particulate matter, also known as black smoke). The filter is a complex system, and it probably doesn't make sense to get into it here. Also, depending on the engine, and company's emissions strategy, new diesels can have SCR systems, to control NOx. SCR systems require a dosing of urea to reduce NOx. As far as I know, all of the companys that utilize an SCR system have it setup so you just fill up the urea tank at the time of each oil change, minimizing the inconvenience. Unfortunately, urea freezes, so they have had to use a tank heating system for engines going to northern climates. All in all, new diesel engines are regulated for emissions, so the "dirty diesel" stereotype should be dead, as any new diesel runs very clean.

3. "Noisy Diesel"
Another stereotype that comes from older engines that rattled and clanked and roared going down the road. There will still be a little more of that diesel growl compared to a gasoline engine, which is simply because you're running compression ignition, and very high compression ratios. In the past years there has been alot done to minimize the engine noise. One huge step was with the fuel system, I believe most engines sold today will be running a high pressure common rail system, which was a huge step in reducing noise. The other improvement is simply from adding more noise deadening/absorbtion under the hood. I have a full size truck with a big diesel engine, and driving down the highway, you wouldn't be able to tell its a diesel, its that quiet. Its louder at startup and under accelleration, but not as loud as they used to be. I would imagine a car would be even less noticable.

4. Lack of filling stations
I think this is a non-problem. I have never pulled into a filling station and found that they didn't have diesel. I wouldn't worry about it.

5. Engine availability
The choices when it comes down to buying a diesel vehicle are very limited. The US is not seen as a good market for diesel cars, so companies don't bother with expensive development projects to develop ratings for US emissions standards. The big 3 were very serious about an expanded diesel offering, but that was killed when GM and Chrysler went in the ****ter. (This really ****es me off, for reasons that some might know, but I can't say anything about it, as it is proprietary) Now they're on the hybrid bandwagon. I don't generally like VW, in fact I think they are pieces of ****, but I would still recommend the TDI, it seems to be a solid engine. Other than that, you can get full sized trucks in diesels and I don't even know if there are any other options.

Responding to the comments on engines not available in certain areas and such, I would guess that the companies had trouble meeting the emissions standards, and took a little extra time to get it figured out. The Tier 4 emissions regulations were an extremely huge hurdle that actually knocked some legendary names out of the market, because they just couldn't figure it out. :cough: CAT :cough:

I probably missed some stuff, but I have a meeting in 2 minutes, post any questions you may have.

[alfablue]

Re: Diesel car considerations

2. "Dirty Diesels"
This is the #1 problem diesels face today, and it isn't even a problem. People that aren't familiar with the new diesel technology instantly think of those old diesels puffing out black smoke. This is not the case anymore, the EPA put an end to those diesels several years ago. New diesels run a particulate filter in the exhaust to control PM (particulate matter, also known as black smoke). The filter is a complex system, and it probably doesn't make sense to get into it here. Also, depending on the engine, and company's emissions strategy, new diesels can have SCR systems, to control NOx. SCR systems require a dosing of urea to reduce NOx. As far as I know, all of the companys that utilize an SCR system have it setup so you just fill up the urea tank at the time of each oil change, minimizing the inconvenience. Unfortunately, urea freezes, so they have had to use a tank heating system for engines going to northern climates. All in all, new diesel engines are regulated for emissions, so the "dirty diesel" stereotype should be dead, as any new diesel runs very clean.
......
Responding to the comments on engines not available in certain areas and such, I would guess that the companies had trouble meeting the emissions standards, and took a little extra time to get it figured out. The Tier 4 emissions regulations were an extremely huge hurdle that actually knocked some legendary names out of the market, because they just couldn't figure it out. :cough: CAT :cough:

I probably missed some stuff, but I have a meeting in 2 minutes, post any questions you may have.

It's possible to meet PZEV with a diesel. It's been done.

It's not about ability, its about cost, and what the customer is willing to pay. Low diesel emissions are VERY expensive. Your truck does have a *cough* catalyst. That's what an SCR is.

Buyers of large diesel trucks are not even close to even an a-typical car buyer.

[bigblue_dl]

Re: Diesel car considerations

It's possible to meet PZEV with a diesel. It's been done.

It's not about ability, its about cost, and what the customer is willing to pay. Low diesel emissions are VERY expensive. Your truck does have a *cough* catalyst. That's what an SCR is.

Buyers of large diesel trucks are not even close to even an a-typical car buyer.

I do not have SCR, my truck is pre-SCR. I have a DOC that runs in coordination with DPF though. We control NOx in cylinder on the line of engines that goes into the pickup trucks, no urea injection required, even with the new engines. (mine is several years old now)

[alfablue]

Re: Diesel car considerations

I do not have SCR, my truck is pre-SCR. I have a DOC that runs in coordination with DPF though. We control NOx in cylinder on the line of engines that goes into the pickup trucks, no urea injection required, even with the new engines. (mine is several years old now)

So you still have a *cough* cat *cough*, then....

[bigblue_dl]

Re: Diesel car considerations

So you still have a *cough* cat *cough*, then....

Oh, I think we're talking about completely different things here. Yes, I definitely have a cat, I'm not arguing that. I was saying :cough: CAT :cough: to rip on Caterpillar for being a huge failure and bowing out of the on-road US market because they couldn't figure out how to meet emissions in time. Talk about an instant 35% bump in market share...

[alfablue]

Re: Diesel car considerations

Oh, I think we're talking about completely different things here. Yes, I definitely have a cat, I'm not arguing that. I was saying :cough: CAT :cough: to rip on Caterpillar for being a huge failure and bowing out of the on-road US market because they couldn't figure out how to meet emissions in time. Talk about an instant 35% bump in market share...

Ooohhh...

That's a different ball of wax. One that put Cat on the wrong side of the happy fence with the EPA recently.

Still- that would be more the MD or HD trucks, and not passenger cars....