Had a person ask me the differences in pollution output between diesel and gasoline engines. Other than telling her that ULSD has a 15 parts per million sulphur output and the efficiency of fuel and torque advantage. She was comparing a R-350 to a R-320CDI and trying to justify her purchase. Thanks ahead.

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1993 300D 2.5L 240,000+ miles

They have to meet the same emissions standards, but the CDI burns less fuel, so by defualt its better for the environment.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Plus, most gasoline she will buy will contain ethanol, which is a major polluter in its production process compared to diesel (or gasoline without it).

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Kent Christensen
Albuquerque
'07 GL320CDI, '10 CL550. '01 Porsche Boxster
Two BMW motorcycles

A lot of people see diesels as "dirty" because of the soot that comes out of the tail pipe. I've had several conversations about this and i always tell people. the emissions from a gasoline engine is clear and orderless and goes straight into the air. that dirty diesel soot is heavy and falls to the ground, and its black. easy to see and clean up. unlike the what you are breathing from a gasoline engine and don't even know it.

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I had the thought the other day that one of the best arguments in favor or diesel cars is that most big trucks, boats, locomotives, and other heavy-use vehicles employ diesel engines, rather than gasoline.

If they weren't more powerful and/or efficient than gas, they would have gasoline engines.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

Pollution differences between gas and diesel engines vary a lot and there are no simple answers. It really depends on what models we're talking about. Both types of engines have made vast improvements in emissions over the years. So it's more about old vs. new rather than gas vs. diesel. Generally speaking if you're comparing an older gasoline engine with an equivalent diesel engine from the same time period, the gasoline engine will typically produce more CO2, CO and HC (unburned fuel vapor) whereas the diesel will typically produce more NOx and a higher mass of particulates (soot/black smoke). I say higher mass, because the gasoline engine may actually produce a higher quantity of ultra-small soot particles that you can't even see but that are more harmful to the lungs than the bigger particles.

Now fast-forward to today, gas engines are generally really clean as long as the engine is warmed up and the car isn't being refueled. Most HC emissions from today's gasoline cars are from refueling. Modern diesels are pretty clean too and they still enjoy lower CO2 emissions than their gasoline equivalents, but are still a bit worse in NOx and particulate mass emissions. However, this is rapidly changing with the introduction of advanced emission equipment like particulate traps. The Bluetec diesels are incredibly clean from what I hear, similar to a gas Civic from a few years ago and probably with lower overall HC emissions.

As far as a R350 vs. R320CDI, the CDI will definitely get better mileage and lower CO2 emissions. The R350 will probably be somewhat cleaner or about the same in the rest of the pollutants.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

Soldiers arent dying for diesel. Need I say more?

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

This isn't about gasoline vs diesel, but rather biodiesel vs diesel: just got back from the emission testing station and the guy gave me the evil eye, as if I cheated or something. He said "what'd you do to your car?".

Turns out the emissions are nearly a quarter of the output since my last test two years ago when I was using straignt petroleum based diesel, compared with the 100% biodiesel I'm running now.

wow

Now that makes no sense. Diesel and gas come from crude...

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The first thing you have to look at is the refining process. Gasoline is a distilate and diesel is a light oil and not as highly refined. Although both are processed from crude it takes more energy to refine and produce a gallon of gasoline than a gallon of diesel. Your net yield in energy is lower on a gallon of gasoline right from the beginning. Then compare the same volume of fuels when they are combusted in vehicles and the diesel releases more energy and is more efficient on each combustion stroke from idle to high rpm.

A winner no matter how you look at it...... high yield, high efficiency, high energy & low emmissions with a little scrubbing!

Cheers

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

What did she mean by "justify her purchase"? The R350 is indefensible. The R320CDI at least gets 33% better mileage.

If she absolutely "must" have an SUV, tell her to buy a Toyota Highlander hybrid (gets better mileage than the R320CDI) and donate the $10,000 she saves to the Nature Conservancy.

The R class is more of a minivan. Very lame IMHO, but its what MB makes in the rest of the world.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

There is an article in the latest road and track. I read it earlier today. It says that the gas engine emits less overall pollutants per gallon consumed than the diesel, but with the better mileage of the diesel it comes out better per mile driven.

iirc.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

WOW!!!

You have to love it. So, did you tell him or not? Did you do anything else to your car? And what model/car is this?

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daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
No longer selling Cluster Needles Paint
No longer selling New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

It is one of the most amazing an overlooked characteristics of a diesel engine in that all you have to do is switch to a cleaner fuel (biodiesel!) and viola.... you have substantially cleaner emissions without doing any type of modification. It is the ultimate "flex fuel" vehicle! It must drive the marketing departments at GM, Ford and whats left of Chrysler nuts as they are desperately trying to push their new purpose built "flex fuel" gas vehicles before the invasion of European diesels to our country in the next 5 years.

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K