MacKenzie conceded that compared to a Hummer, the Prius looks pretty green, and acknowledged that its emissions are cleaner than some of those aforementioned European compacts and subcompacts.

His point? There’s no “silver bullet” yet unveiled that will solve our emissions problems “all at once, all the time.’’

We can agree with that. Which brings us to our test drive, and the Prius, which is at least, green right now…. That is to say, it’s about as green as it gets in America, and we’ll be happy to look down the road for some of those European models coming our way, such as the new Smartfortwo by Mercedes.

We set out on our test cruise on a beautiful warm fall morning with salesman David Darty of Toyota of Dallas. Darty, a former Navy man, was expert at explaining the car’s features while we drove. But then he sells Priuses all the time, to soccer moms stepping down from SUVs, grandparents with grandkids to cart around and even a couple Mercedes owners – all concerned mainly about “doing the right thing.’’

The first gizmo we fell in love with was the navigation panel. It could talk us through directions in map mode or, on another screen, show what was going on with the engine.

This engine pictorial was a fun feature. It told us our estimated miles per gallon as we drove and showed a picture of how the power train was working. We could see when we were powered by gas or by the electric motor and confirm that yes, indeed, the battery was charging when we stepped on the brakes. How this “regenerative battery” feature worked was complex, but the simple upshot for consumers is that the battery gets recharged during normal driving so you don’t have to plug it in anywhere later.