I'll reply like I always do to questions about wheels or any other item you might want to add to the car: do whatever you want, and whatever gives you the most enjoyment from your car.

No matter what you end up doing to your HCH, you will still be getting 20-25 percent better mileage than you would from a regular Civic, driven and equipped in a similar manner. There is a ton of empirical data to show this, from owners, magazines like Consumer Reports and Road & Track, and automotive writers.

And if you become captivated by the desire to get even better mileage, like almost everybody here does, then you will get even better results -- 30-50% better, by my own experience.

So, you will be greatly enjoying your car, and you will be supporting hybrid technology, and you will be using less gas, and you will be polluting less.

What's not to like?

ps: I voted "don't care" simply because I think it's your own choice to make.