From the Forums: Buy a New Car or Keep Old One?

new cars

BAF is caught in a difficult position:

I have a 1996 nissan minivan, 21 mpg, paid off, runs great. I drive about 10,000 miles a year, so that's roughly 475 gallons of gas per year, and about $1750 a year spent on gas (at $3.60 a gallon).I know that economically it is better to hold on to my old car...if I doubled my gas milage I save about 800$, which is a lot less than a new car payment.
But what about the environmental impact of an older car? If I want to REDUCE, I won't dump a working car just for something shiny and new. I can also REDUCE by walking/biking etc when possible. But in terms of driving,is my carbon impact bigger if I buy a new car (impact of manufacturing, etc) or bigger if I drive my older car (less mpg).

Looking at todays market, my pocket book, and my family's needs, we would replace this van with a Honda Fit (33/38mpg). I really need a hatchback, prefer 4 doors, and am not seeing a hybrid that would suit our family at this time. Another bonus of holding on to my new car, is allowing the market to make some more advances in hybrids, and maybe even an electric car?? I live in Eastern Washington, near the Columbia River dams, with lots of cheap hydroelectric power.
So, I appreciate anyone's advice. Hold on to the old car, or switch to the Honda Fit...what is best for the environment?

So what do you think? Have any advice for BAF? What about a vehicle recommendation? Come in and share it.