Cleaner diesels' day in the sun?

Compared to diesels of the past, this is indeed an improvement.

Compared to other vehicles available, this is very disappointing.

Until they actually earn a SULEV or PZEV emission rating, they are not clean. Heck, for that matter they are still dirtier than an ordinary Corolla. Of course, Mercedes isn't exactly a cost-competitive vehicle anyway.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 4 2006, 01:05 PM) [snapback]343804[/snapback]</div>

Well if shouldn't, for years gasoline engines continually got cleaner fuel through new refining processes at a demand from auto manufactors.

Diesel was left in the dust literally since it wasn't important to anyone. Now ULSD is out and the new emission standards for diesels in '07 means we will be burning cleaner then Europe.

Diesels have had a handicap in emissions til just recently. On a basic technical concept they burn cleaner then a gasoline engine by default but like gasoline engines are subject to varying amounts of load which affects this. They also last longer and with lower soot levels in the oil(from combustion) and fuel this is doubley true.

Diesels are the future even when hydrogen is a worldwide fuel. Clean fuel was the last handicapp since the technology was already there just couldn't be utilized.

 

<div class='quotetop'>QUOTE(Thermo1223 @ Nov 17 2006, 10:28 AM) [snapback]350809[/snapback]</div>

However, not a single automaker has plans to actually use that hardware. Sure, we've seen PZEV diesel prototypes. But all that's scheduled to be delivered for 2007 model year is just the "50 state emission" criteria ...which is a pitiful level, dirtier than average.

 

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 4 2006, 12:05 PM) [snapback]343804[/snapback]</div>

Yeah black smoke is still there, I know a guy with a 2004 Jetta TDI that smokes pretty visibly. Hopefully ULSD and emissions systems designed for it will help to eliminate all visible exhaust.

I wouldn't hold my breath for a SULEV or PZEV diesel engine, meeting Tier 2 bin 5 is sufficiently challenging for manufacturers at the moment. Part of the problem with controlling diesel emissions is because of the makeup of the exhaust. A diesel engine runs lean for the majority of the time, which means excess oxygen in the exhaust. Excess oxygen makes it hard for a catalytic converter to do much about nitrogen oxides, which is why elaborate NOx reduction systems are required. NOx seems to be the barrier holding diesels from getting cleaner ratings.

 

<div class='quotetop'>QUOTE(seftonm @ Nov 17 2006, 09:50 PM) [snapback]351289[/snapback]</div>

I was reading the other day (too lazy to look it up) about the Mercedes system using urea which has to replaced every 6 mos or so. Will it just stop when it runs out? Doubtful. Probably a blinking dash light which will be covered by duct tape until just before smog check time!

 

<div class='quotetop'>QUOTE(RonH @ Nov 17 2006, 09:32 PM) [snapback]351299[/snapback]</div>

Refill is supposedly every 15k miles. If that's the case, it would probably be done at each oil change. Of course, there's still the problem of people who don't take their cars to the dealer. Throwing a check engine light probably won't be enough to make the EPA happy so the car may have to do something like have significantly reduced performance until the tank is refilled.

 

<div class='quotetop'>QUOTE(seftonm @ Nov 19 2006, 04:19 PM) [snapback]351802[/snapback]</div>

Really? My research estimate is half that.

For every gallon of diesel, 4 percent of a gallon of AdBlue is required. With efficiency averaging about 45 MPG (yes, I know, that's highly unlikely for an automatic diesel in mixed driving) then about 6.7 gallons would be needed for 7,500 miles.

7 gallons is about all the physical space an automaker would likely be to sacrifice for a mid-size sedan, especially when you consider room for refill access is also required.

 

Mercedes says AdBlue efficiency is 2,352.15 mpg. If that figure is used, 15k miles needs a tank roughly 6.5 gallons big (Link). Apparently, one area the EPA is exploring regarding urea refills is that the refill interval must be at least as long as the manufacturer's oil change interval which is around 13k miles for the E320 Bluetec.

 

<div class='quotetop'>QUOTE(john1701a @ Nov 4 2006, 01:11 PM) [snapback]343809[/snapback]</div>

They are very clean if you consider the CO2 output which is what the rest of the world worries about.
They are less clean from a NO2 output which is what the USA worries about. (still pretty darn good though)

 

I think the diesel option is a good idea. Better mileage, higher yield per barrel of oil vs. gasoline and it mixes well with soybean oil. Sign me up!

 

<div class='quotetop'>QUOTE(Hornhonker @ Dec 5 2006, 12:53 PM) [snapback]358048[/snapback]</div>

Ever see the smog in China?

As for making a choice, anyone insisting we have to is not being objective. *BOTH* types of emissions are a problem. Sacrificing one for the sake of another is totally inappropriate, since hybrids clearly prove that isn't necessary.

With a hybrid like Prius or Camry, you get both CO2 and NOx reductions. So the MPG does not come at a penalty. You really can have it all... something that the non-hybrid diesel supporters continue to oppose.

 

Smog in China is due to heavy dependence on coal for energy and outdated emissions regulations and control systems.

I am a diesel supporter and owner but don't oppose anything hybrid related. Hybrids are a great idea but I simply felt that a diesel was better suited for my uses than a hybrid. A diesel car meeting 2007+ emissions requirements is better for the environment than a gas version in my opinion, plus it cuts down on oil use. Hybrids are better emissions-wise than diesels however they also cost more (so far at least), and to me, they are less fun to drive. Any vehicle with a gasoline engine has at least one emission downside compared with diesel: volatile organic compounds, which are an ingredient in smog like nitrogen oxides.