Yahoo has published their top 100 green cars. Personally, I plan to go car-less in the next month (more about that in later posts), so I'm not really interested in buying another car. However, I find Yahoo's ranking system quite interesting. They apply the concept of "lifecycle assessment ... the scientific method for adding up all of the environmental damages associated with a product".

They include the major pollutants in the rating system (which are produced during manufactoring as well as actually operating the car):

• Greenhouse gases, primarily carbon dioxide (CO2)
• Fine particles (particulate matter, PM)
• Nitrogen oxides (NOx)
• Hydrocarbons (HC)
• Carbon monoxide (CO)

You may have this desire to sell your car and go green and buy the one at the top of the list: the Honda Civic Hybrid. But its still worth thinking about the financial implications.

I was curious what this would mean to my retirement if I went and bought this car today. I used yahoo's estimates for the cost of ownership, but removed anything related to financing (to keep it simple). I stuck to just using their costs for fuel, maintenance, insurance, and repairs for five years.

The total cost of ownership for me $14,089, plus the cost of car, at $23,650, totals out to $37,739.

So now the fun part: invest that into the market with an average return of 7% until I retire (37 years for me), and I end up with $461,307 (I used our interest calulator to compute this)!

If you want to play around with the numbers a little more, check out this site - they include the costs to finance, as well as other variables.

I think I'll keep riding my bike to work....