Scooters are gross polluters?

Have you seen the newspaper and TV articles asserting that a scooter pollutes more than an SUV? Shocking! Sounds like we should all drive around in SUVs...until you take a closer look at the testing methodology.

1) Pollution in these tests is measured in parts per million -- in other words, what percentage of the exhaust is pollution? They ignore the fact that a 50cc (or even 150cc) scooter produces a much smaller volume of exhaust than a 3000-5000cc (3-5 liter) SUV. Why not a test that shows total amount of pollutants leaving the exhaust pipe of each vehicle? Ten is less than twenty, but ten percent of Bill Gates' net worth is substantially greater than twenty percent of mine.

2) Not all pollutants are created equal. The tests lump together unburned hydrocarbons, CO, and CO2. 2-stroke engines are designed primarily for performance -- to produce lots of power with a little engine -- and unburned hydrocarbons in the exhaust are one of the unfortunate side effects. What are unburned hydrocarbons? Gasoline that wasn't burned by the engine. Those wavy vapors you can see emanating from a gas station on a warm day? Those are unburned hydrocarbons too. CARB (California's emissions agency) worries about unburned hydrocarbons, because, in warm sunny conditions, these can turn into smog. However, without this warmth and direct sunlight, smog does not form. The unburned hydrocarbons find their way up into the atmosphere, where they break down into carbon dioxide -- just as they would have if they'd been burned by the engine.

If you're worried about your carbon footprint or global climate change, then pick the vehicle that will take you farthest on a gallon of gas. If you live in a location where smog is a recurring problem, pick a 4-stroke scooter, preferably one that has fuel injection and a catalyst exhaust. But don't be fooled into thinking that your scooter is a gross polluter -- in terms of total emissions into the environment, your little 2-wheeler is still better than an SUV. And don't forget bicycling or walking!

Misguided article from Portland paper