I think you are exactly right. I am in this category and I didn't do it to save money because I couldn't afford gas or believe I won't be able to in the future. However, I don't like spending money on gas when I don't need to, so I kind of viewed it as not wasting money on gas, rather than saving money overall. In the past few months I also installed a solar pool heater, new energy efficieint air conditioners and furnaces, and replaced over 50 65W floodlamps with 14W compact fluorescents. I did those things for similar reasons. Spending less on energy, in conjunction with using less and creating less CO2 is just kind of satisfying to me. I didn't do any real analysis to see when I would "break even", if ever.njkayaker said:For the relatively wealthy average driver, MPG is largely a non-issue! And if one is in this group (wealthy average drivers) and one buys a Prius, the reason behind the purchase isn't to save money! (One would need to be relatively wealthy and drive lots of miles to be able to afford a Prius and to justify it economically).