They sip gas, but sometimes belch

The lighter weight and smaller engines of motorcycles have allowed them to get better gas mileage than cars for decades. Priuses and other hybrids are finally catching up to the 50+ mpg that many motorcycles get, and have gotten for a while. Heck, the indestructible Kawasaki KLR650 � the Swiss Army knife of motorcycles � which has been around since 1987 and has remained mostly unchanged until 2008, has always been able to eke out upwards of 50 mpg from its 650cc single-cylinder engine. Just like cars and trucks, motorcycles come in every shape and size, and some do better in the mpg category than others. But, even Harleys � for as loud and obnoxious as they can be � get significantly better gas mileage than most cars on the road.
Though two-wheeled transportation generally gets great mileage and produce little CO2 thanks to their small engines, sadly, many motorbikes and scooters emit more hydrocarbons and nitrogen oxides than cars. Part of the problem here is that regulation has not forced motorcycle makers to keep up with their auto making counterparts. A report published in 2006 showed how motorcycles emit more of these global warming gases per Km (the authors are from Switzerland) than cars. There are a couple caveats about the report. The motorcycle data is an average of 8 scooters and motorcycles; some have two-stroke engines and others have cleaner burning four-stroke engines, and some were quite old and worn at the time of the testing. Anyone who�s piloted a lawnmower knows that two-stroke engines, especially older ones, spew evil into the air.
New motorcycles and scooters have already improved significantly compared to the older ones tested in the study. Europe is already in the middle of timetable which is significantly cleaning up motorcycle and scooter exhaust. In a recent study by France�s government, motorcycles which comply with Euro3 standards use less gas, produce less CO2 and total greenhouse gases than cars which meet the more recent Euro4 standards (here and here).
Then there�s the real world advantage that motorcycles and scooters provide over autos. In urban areas, motorcycles and scooters provide for a quicker trip on average from any A to B. Two wheels are often able to scoot right through most urban gridlock situations, and take far less time to park compared to cars (or Ford Excursions) once B is reached. Simple math: Less time with the engine running equals less pollution.
As you may have guessed, regulation in the US is far behind Europe. In 2010, the EPA is going to largely align federal emission standards for motorcycles with California�s regs.
I don�t want to toot my own motorbike horn, but my ride is 1996 BMW R1100RS which is actually quite good - even by today�s standards - in the emissions department. It�s fuel-injected two-cylinder with a catalytic converter and has modern engine performance measuring doohickeys like O2 sensors. Not bad for a more-than-decade old motorbike. Economically speaking, not bad for me either, considering it cost me less than 1/5 the price of a Prius. Though, a Prius is nice on a rainy day.

Tweet