A couple days ago, we got some great feedback about our story refuting press reports about scooter emissions, notably Cecil Adams’ syndicatedThe Straight Dope column“Give a Scooter, Pollute Her.” The way Cecil framed the question left us doubting his conclusions, but we admitted there was something to his findings, and wondered about specific emissions figures.
Well, 2SB reader “JSH” tracked down some real numbers, and his comment was so thorough and insightful, we’ll just reprint the whole thing here:
Cecil’s story is quite accurate. As he said, it really depends what your goal is. If you are interested in reducing CO2, energy security, and global warming than scooters are the clear choice. If you are concerned about smog forming emissions regulated by the CARB and the EPA then scooters, even 4-strokes, are gross polluters compared to even SUV’s.
My only issue with Cecil’s story is that he compares emission standards, (the amount of pollution a vehicle is allowed to emit) instead of actual measure emission. Data for actual emission is easily available, all one needs to do is go to CARB’s website and look at the certification data. Here you will find the actual emissions data submitted by manufacturers to CARB in order to certify that the vehicle meets emission regulations. This data is collected by running the vehicle through a uniform test and measuring the emissions.
Some Scooter data:
Vehicle HC CO NOx Total Aprilia Scarabeo 100 0.200 1.000 ? 1.200 Vespa LX 150 0.100 5.000 ? 5.100 SYM HD 125 0.900 1.000 ? 1.900 Genuine Buddy 150 0.400 7.000 ? 7.400 Genuine Rattler 110 0.900 7.000 ? 7.900 SYM HD 200 0.700 4.000 ? 4.700 CARB Regulation 1.000 12.000 ? 13.000
(Note: All numbers are grams per kilometer, scooters are not tested for NOx)
As you can see actual, scooter emission vary wildly but all are much lower than what CARB allows. One can’t really stereotype 2-stroke vs 4-stroke either. While the Rattler 110 is a 2-stroke and is the most polluting on my list it is only 7% worse that the 4-stroke Buddy.
Car and SUV data:
Vehicle HC CO NOx Total 2010 Toyota Prius 0.031 0.025 0.002 0.058 2009 Suburban 6.0L 4×4 0.026 0.559 0.012 0.597 CARB Regulation 0.056 2.600 0.043 2.699
(Note: All numbers in grams / kilometer (converted from grams / mile)
Again, vehicles vary widely but even the worst cars and SUVs are well below the emission standard. However, even the best scooter emits 20x more pollution than a Prius and 2x more than a 4×4 Suburban.
So again, it depends on what one is more concerned about. If one is more concerned about the air quality of their city than any car is better than a scooter. If one is more concerned about reducing the consumption of gasoline and other natural resources than a scooter is the better choice.
Well done, JSH, if your research and math is correct, we’re convinced, and very disappointed (Our apologies to Cecil Adams, too).
It was always hard to believe scooter manufacturers’ vague ecological hype, but on the other hand, it seemed impossible that modern 4-stroke scooters could be bigger polluters than cars. Even so, they have other benefits, but it’s hard to see past these numbers comparing actual emissions per kilometer.
As far as we’re concerned, these numbers put a pretty serious dent in any argument that scooters are “green” or environmentally-friendly, and lower gas prices temporarily put the fuel economy arguments to rest (which are also overstated in most cases), maybe now we can all get back to riding scooters because they’re fun and practical.