Sorry to bring up this heated debate, but I searched on "Environment", and this was the only thread I found that was somewhat related.

Anyway - Does anyone know how a 2 stroke motor that gets 120 MPG compares to a regular automobile that gets 30 MPG?

Environmentally - how does a 2 stroke compare to a 4 stroke?

Just by doing simple math, I would have to imagine that a 2 cycle would have to be 4 times the polluter that a car would be before you can claim that it's worse for the environment than driving a car.

I would have to imagine this topic has been brought up before. If someone could post a link to more info, I'd greatly appreciate it.

Edit: Answered my own questions via Google: A typical 2 stroke marine engine only burns 70% of the fuel it uses as compared to up to 97% on a 4 stroke.

Click here for source

So that's 3% pollution on a 4 stroke as compared to 30% on a 2 stroke.

So you'd have to get 10 times the MPG on a motorized bicycle with a 2 stroke to be more environmentally friendly than an automobile.

I also found several articles about how 2 stroke engines on motorcycles and 3 wheeled "tuk-tuk" type vehicles are the major cause of air pollution in developing countries.