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2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 4:21 am
by akskoot
My friend, who is a career oil man engineer type, claims that my scooter is worse for overall emissions than an auto, despite mpg. I would love to hear some informed conversation about this topic as I always thought I was doing my green-civic-duty by driving my scoot instead of the truck. Are we two-wheeled 02 spewing dinosaurs?

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 6:14 am
by Lunytune
Last winter Michigan had the coldest winter in history.

There were no scooters when dinosaurs were on this earth. So how could have been manmade devises that killed them. In fact, if you listen to evolutionists, man did not occupy the earth at same time as the dinosaur. There is more than a little incongruency in their theories.

If I lived in California where the wind doesn't blow, I'd be concerned. In fact, there's another incongruency. If emmissions rise up to cause higher stratus problems, how is it that we have smog?

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 8:18 am
by veedubh20
tell him go try run castor 927 oil :mrgreen:

Hawaii is the only island has no smog test compare to any 49 states.. :D

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 8:41 am
by wiguy05
Lunytune wrote:Last winter Michigan had the coldest winter in history.

There were no scooters when dinosaurs were on this earth. So how could have been manmade devises that killed them. In fact, if you listen to evolutionists, man did not occupy the earth at same time as the dinosaur. There is more than a little incongruency in their theories.

If I lived in California where the wind doesn't blow, I'd be concerned. In fact, there's another incongruency. If emmissions rise up to cause higher stratus problems, how is it that we have smog?
* are you rambling about? :?

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 1:38 pm
by Bear45-70
Two strokes by their design allow apart of the intake charge (fuel and air mixture) to go out the exhaust port. These heated but unburned gases cause an unbelievably high NOx output by 2 strokes. So yes, a 2 stroke with a carburator are major polluters when compared to 4 strokes. When you compare Electronic Fuel Injection 2 stroke to EFI 4 stroke, the 2 stroke is even worse because of the unburned fuel and air mixture still going out the exhaust port. Then there is the Direct Injected 2 stroke, where there is only air coming in the intake port and going out the exhaust during the exhaust scavenging cycle. The fuel is injected directly into the cylinder and is timed so that the fuel never reaches the exhaust port before it closes. These engine are more powerful, more fuel efficient and have cleaner exhaust than the 4 strokes do. So the answer is, "It depends on what type of 2 stroke you are taking about."

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 2:38 pm
by Clivester
I haven't researched this enough to find a well supported argument to really show that 2 stroke scooters are worse for the environment than cars. I agree that in general the older 2 strokes are "dirtier" when it comes to emissions. However, there are many ways to make comparisons. Are we talking emission level per cc, emissions per vehicle, or (probably more appropriately) per person miles driven?

Furthermore, its often overlooked that a scooter probably creates far less "carbon deficit" to manufacture than a car due to the very large difference in quantity of materials.

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 2:45 pm
by Arnadanoob
Bear's right on it again.

2 strokes on mopeds have a unsolveable overlap period where both the intake and exhaust ports are wide open which allows a lot of unburned fuel to escape into the environment. This produces a ton of unburned hydrocarbons (UHC) which are very toxic. Ontop of this 2 strokes burn oil at a much higher rate than any decently maintained car. Using the vegetable-based Castor 927 oil as veedubh20 has stated helps a little with that but it won't bring 2 strokes towards 4 stroke efficiency, not even close.

Combine ECU controlled ignition, valve timing and fuel injection to a simple moped carb, there's no comparison. Now add an O2 sensor and catalytic converter(s) and EGR (exhaust gas recirculation) and you'll clearly see that a car is superior for emissions. Cars are getting even better as they design them for ultra lean burn ratios which mopeds cannot come close to matching without blowing up the engine.

The argument about how mopeds gets xx MPG vs a car is all about the 2 stroke advantage. Given the same displacement a 2 stroke engine will produce anywhere between 25-50% more power than a 4 stroke counterpart. The simplicity of the 2 stroke engine, considerably lower weight and higher power all contribute to the results. Emissions is where the 2 strokes fail.

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 6:24 pm
by Lunytune
wiguy05 wrote:* are you rambling about? :?
I'm sorry. I thought intelligent people would catch the gist of the thread. It's about "pollution" and "global warming". Please read and you won't need alliterated explicities.

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 6:44 pm
by Spreetard
Lunytune wrote:Last winter Michigan had the coldest winter in history.
It sucked. true story.

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 8:09 pm
by akskoot
Lunytune wrote:
wiguy05 wrote:* are you rambling about? :?
I'm sorry. I thought intelligent people would catch the gist of the thread. It's about "pollution" and "global warming". Please read and you won't need alliterated explicities.
:lol: Nice notice it is about pollution, but not "pollution". That's the kind made up by the liberal media to justify taking away your guns and muscle cars. :lol:

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 11:09 pm
by eliteguy50
Arnadanoob wrote:Combine ECU controlled ignition, valve timing and fuel injection to a simple moped carb, there's no comparison. Now add an O2 sensor and catalytic converter(s) and EGR (exhaust gas recirculation) and you'll clearly see that a car is superior for emissions. Cars are getting even better as they design them for ultra lean burn ratios which mopeds cannot come close to matching without blowing up the engine.
check out the 2008+ zuma 50, there is a lot of that cali influence epa crap and it sucks.
Clivester wrote:I haven't researched this enough to find a well supported argument to really show that 2 stroke scooters are worse for the environment than cars. I agree that in general the older 2 strokes are "dirtier" when it comes to emissions. However, there are many ways to make comparisons. Are we talking emission level per cc, emissions per vehicle, or (probably more appropriately) per person miles driven?
right on. if you go by emissions per unit of fuel then yes 2 stroke is not as clean, but if you go by the mile then that changes it because you could easily cut that down to a fourth if not more, depending on the vehicle.
akskoot wrote:claims that my scooter is worse for overall emissions than an auto
overall % yes, but over the course of a year...the car will burn 4 times more gas but does it burn more than four times as efficiently to even out the total?

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 11:15 pm
by mr pibbs
Am I wrong to say that a gallon of gas creates the same amount of emissions if it is burned, evaporated, or whatever?

Re: 2-smoke emissions vs. auto emissions

Posted: Thu Aug 13, 2009 11:37 pm
by Bear45-70
mr pibbs wrote:Am I wrong to say that a gallon of gas creates the same amount of emissions if it is burned, evaporated, or whatever?
No, It is just not that simple.

Re: 2-smoke emissions vs. auto emissions

Posted: Fri Aug 14, 2009 2:42 am
by Kenny_McCormic
mr pibbs wrote:Am I wrong to say that a gallon of gas creates the same amount of emissions if it is burned, evaporated, or whatever?
Gasoline burns very very very dirty unconfined and uncontrolled.

Re: 2-smoke emissions vs. auto emissions

Posted: Fri Aug 14, 2009 7:31 am
by Lunytune
Kenny_McCormic wrote:
mr pibbs wrote:Am I wrong to say that a gallon of gas creates the same amount of emissions if it is burned, evaporated, or whatever?
Gasoline burns very very very dirty unconfined and uncontrolled.
http://www.southernskies.net/page_info/ ... ngine.html

The two stroke is much more efficient than we give it credit for.
The fuel IS confined and IS controlled more than you think. The sonic compression wave of a properly tuned exhaust resolves the majority of the fuel that comes through due to the overlap of intake and exhaust. What is so obnoxious to us is the fumes from the oil, not the gasoline, and that has been reduced considerably from the 1 in 16 common 50 years ago to 1 in 50 now. We would produce far less emissions if we would trust our oil and injection system instead of pouring extra oil in the tank.

Europe is possibly the most politically correct continent when it comes to Global Warming and air quality control, yet it is there where the majority of 2 strokes are. Scooters are everywhere and nobody seems to complain. I think our mindset is politically created, not realistic.

Yamaha has pretty much thumbed their nose at the politically correct thinkers and continues to build 2 strokers which they built their fame on. Honda, on the other hand, has yielded to the pressure in the move to 4 strokers. And that's why we Spree/Elite lovers do what we do. So don't try to make me feel guilty with all this politally correct jargon. :mrgreen: