Pulse and glide should be called Pulse & Pollute

[rmay635703]

I have long since believed that the volume of pollution is far more important than the quality of it. Even when pollution is 100% clean it is still CO2 & CO.
If you get dramatically better FE it simply is not possible to be emitting the same volume of pollution. Each gallon of gas converts into a specific amount of pollution regardless of its cleanliness.

Also studies are showing that sulphur may help with global cooling, maybe sulphur in diesel wasn't a bad idea especially in rural areas where the effect is a little fertalizer and not smog.

[NachtRitter]

Originally Posted by hackish

Unfortunately I haven't had the time to properly compile the data but from what I've seen it appears that shutting the engine off on my 1993 honda civic VX and then restarting it after only a 20 second coast produced approx 4-6x the pollution as running it for the same 20 seconds.

I would still like to see this data you speak of... even "pre-compiled"

[autoteach]

this reminds me of the new DPF's on trucks. To get rid of the particulate they trap it and then burn it at a high temperature with more diesel. This ends up netting less PPM of the bad stuff, but more Millions of all the stuff, as MPG suffers.

[abently]

Originally Posted by dcb

not really sure the sensationalized title is all that accurate. You have to have controls and reflect what people are actually doing to have a reasonable test.

lol

Data is indisputable, so do that when you can and I'm sure we will crunch the numbers for you.

[dcb]

where does one find a portable 3 gas analyzer for cheap?

[roflwaffle]

Originally Posted by autoteach

this reminds me of the new DPF's on trucks. To get rid of the particulate they trap it and then burn it at a high temperature with more diesel. This ends up netting less PPM of the bad stuff, but more Millions of all the stuff, as MPG suffers.

t's not too bad, something like ~.3+mpg for a ~20mpg diesel pickup truck.

[autoteach]

well, there are many people claiming a 3mpg gain with a dpf delete.

[roflwaffle]

Do that have documentation? The only thing I could think of to explain that would be a wonky DPF system or if the engine was a real NOx queen.

Edit- It looks like all the DPF kits come w/ something that flashes the ECU, which is probably where any mileage gains are coming from.

[Piwoslaw]

Diesel particulate filters are almost mandatory on European diesels (hard to pass new emissions standards without one), but I'm not sure how eco-friendly they are on a global scale. Yes, they reduce particulate matter almost to zero, but they need to be burned out every now and then. When initially testing emissions and fuel economy for a new model, the car is new and the DPF is not clogged. I wonder how those tests would go during a burnout?

For PSA diesel engines (Peugeot/Citroën, but also certain Fords, Volvos, Subarus) there is a fuel additive called Eolys, which is about 5% cerium and 80%-90% hydrocarbons. When the ECU initiates burnout, fuel is added to raise exhaust temperatures, and the Eolys fluid is injected into the fuel going to the engine, lowering the temperature at which PM starts to burn (from 550°C to 450°C). The cerium does not burn, but stays in the filter (I believe it binds whatever is left over after burning the PM). After a while, this cerium residue starts to clog the DPF and it should be replaced after 120k km.

VW also has a DPF technology with a urea-based fluid.

So, at its best, a PF diesel is very clean. But if it is driven efficiently (=low exhaust temperatures), then it will be burned out quite often (=more fuel+additive) and will need a replacement filter sooner (=extra resources, not to mention costs). EO(ff)C-ing a diesel with a PF may lower the already low temperatures even further, but then new, hi-tech turbodiesels shouldn't be cycled on and off too often. If you go racing on the Autobahn every now and then, then you're OK, but for everyday driving your ECU is going to start adding fuel (and fuel additives) every so often.


Another question: If we are concerned about catalyst cooling, then should we be DFCOing? When engine braking, air is pumped through the engine, then through the cat, cooling it from the inside. Yes, compressing it inside the cylinders raises its temperature somewhat, but upon exiting it is still much cooler than during normal combustion, and so also cooler than the cat.

[dcb]

Perhaps CO and hydrocarbons might be doable affordably, plenty of inexpensive home CO and combustible gas monitors in the market. NOx is a little harder to come by. But yah, the CO2 isn't a welcome pollutant either, plus everything it took to get the extra fuel in your tank that P&G saves.