Cheating on Emissions: Nearly All New Diesel Cars Over Limits; Tractors Next?

[5030]

I do.

Never anticipate anything. You may be or you may not be....

 

[GoldenCityMuse]

Plan for the worst, Hope for the best. That is one of my aims in life.

 

[buickanddeere]

I can't get excited about tractor NOx. Most of them are used out in the country. NOx problems are city air problems.

Diesel will give lower almost anything else (if there's a soot collector) than a gasoline engine just because it'll use 30% less fuel than a carbureted gasoline engine. When they start putting fuel injection, etc. on the gasoline models to lower their emissions to those of cars and trucks, then the only way diesel can get much more than 20% (difference in fuel energy values) ahead is with turbo charging.

Ralph

Please share with us the proof of that statement

 

[buickanddeere]

We'll all be driving Tier 4,5,6, whatever the number reaches, if we live long enough.....

The new age, new world order, Agenda 21 types in the EPA. They had hoped that Tier I & II would financially cripple the use the diesel engines. The Tier III & IV would effectively ban diesel engines.
Don't worry, the EPA is working on Tier V & VI.

 

[RalphVa]

Emissions and fuel economy go hand in hand, except for NOx. Diesel makes more NOx and soot. I've heard some people say that their clean diesel tail pipes are cleaner than one on most gasoline engines though, because there's no soot collection on a gas model.

When we were engineers in the 70s, we did a survey of fuel economy on our cars and trucks. We had about an equal # of diesels and gas models. The gas models (all with carburetors back then) ran 30 mpg-ton. In other words, a one ton car (and most economy models were almost exactly that back then) would get 30 mpg. The diesel correlated @ 45 mpg-ton. No turbo engines.

In the meantime, turbo charging and fuel injections have come along. In my rough estimate from observation of mpg changes with these, fuel injection generally will improve fuel mileage by around 20-25%. Turbo charging is good for another roughly 25%. So, you can easily see where a fuel injected, turbo-charged gasoline model will almost make that 50% gap we observed. Throw in computer control (e.g. shutting off fuel when coasting, etc.), hydro fans and electro mechanical steering in place of power steering pump, and you can easily see how gasoline-engine vehicles will get probably better mileage than a plain diesel engine. Put turbo on the diesel with the same goodies, and it'll be 20% better IF it doesn't lose anything via diesel regens on the exhaust system. Unfortunately, the diesel regens (usually done with a tiny bit of fuel injection increase to start the burn) go a long way to killing that 20% advantage. A typical high mpg diesel car (like a Cruze TD or VW Jetta TDI) with urea injection will do 46 mpg average. The equivalent gasoline model with turbo will do 39-41.

In actual testing, one tester showed about 49 mpg on a Jetta TDI on the hwy while a Mazda3 did 47. The Mazda3 is about 200 # lighter than a Jetta though, about the same as a Golf.

Ralph

 

[buickanddeere]

When comparing we should set the terms. Per gallon, $$$ per mile, Per btu or what .

 

[OkieDave]

When comparing we should set the terms. Per gallon, $$$ per mile, Per btu or what .

I linked to the actual standards; click the link and you'll see that it's grams (of emission) per kilowatt-hour.

 

[3930dave]

Some of the latest NON Diesel scams....

Audi Lawsuit Alleges Cars Emit Illegal Carbon Dioxide Emissions | CarComplaints.com

Once dyno based (ie. not computer 2 computer "chatting") tail-pipe testing stopped, many manufacturers said "Game On", independent of fuel used.

Rgds, D.

 

[DieselBound]

Diesel engines, all other things being equal, will ALWAYS get better FE because the fuel has more BTUs. I think diesel (D2) has about 13% more BTUs. Out of the gate the diesel has a head start by virtue of this fact.

 

[MHarryE]

Study internal combustion engines and you will find in their current form, diesel will always get better fuel economy than gasoline. Its the diesel cycle vs Otto cycle. Engineers can screw things up but the trend has been to optimize for better fuel economy. The Tier 1 engine I installed in a machine in 1995 was 4.4 liter and maxed at 107 HP. Now that same engine with common rail fuel system plus other major improvements gets 200 HP out of the same 4.4 liters. Less swept area vs a 6.6 liter 6 reduces friction. Pumping loss improvements, more efficient combustion, using more of the oxygen, better turbos, etc., all add up. On the other hand has engines have also improved. My 2015 Ecoboost gets 30% better fuel economy on my yearly average vs my 2005 5.4 liter. Compare it to my partners F-250 diesel pulling a load and I lose big time on fuel economy although we match on acceleration. He beat me by 40% pulling the same weight load roughly 200 miles. However I usually drive lightly loaded while he pulls the heavy loads. On light loads my gas truck shines.