The guys at Mythbusters try to answer what pollutes more, a car or a bike.
http://www.youtube.com/watch?v=Cm3fGVYo--U
http://www.youtube.com/watch?v=EjCUHyn36ZM
http://www.youtube.com/watch?v=CMxsKoys2dU
http://www.youtube.com/watch?v=ooGe-TVIx9M
there are a few problems with the test that i dont agree with, but i’ll let you watch and decide what you think