Zippcar, the world’s largest car sharing service, is an alternative to traditional car rental and car ownership. You join and get a Zipcard that unlocks thousands of cars around the world. Drivers rent by the hour. Gas and insurance are included in the price and there’s no minimum commitment. It’s considered a “green” alternative because it gets cars – they estimate 12 to 20 personally owned cars for each Zipcar used – off the road. Has some real face-validity to it.

“Green” and “sustainability” have, of course become more important elements of most product and service categories in recent years. A number of years ago the aspect of “green” got so important in Athletic Shoe category that the ‘Materials and Manufacturing’ engagement driver had to be renamed to – no pun intended – the ‘Carbon Footprint’ driver. So we weren’t all that surprised to see “green” increase the percent-contribution it makes in the Car Rental Category as well. To be fair to all brands, there isn’t a whole lot of differentiation in that area, and they’re cars, after all, and currently Zipcar is too small to show up on our National survey, but that said, here’s how the brands rank versus the Ideal in being perceived as “green:”

1. Avis (58%)
2. Hertz (57%)
3. Enterprise (56%)
4. National (53%)
5. Budget (50%)

Avis used to be the brand known for “working harder,” but in this case Hertz is rolling up their sleeves and revving up their brand engine and taking a run at the rent-by-the-hour marketplace – and Zipcars’ green positioning – by letting eco-conscious New Yorkers rent plug-in autos by the hour beginning the middle of this month.

The company is offering an all-electric Nissan Leaf, a virtually silent mode of transportation with a top-speed of 90 MPH, which defuses the joke how do you make an electric car go faster? A tow truck. If you’re interested it will cost you a $50 membership fee and around $7 an hour. It takes 8 hours to charge at a specially designed charging station, and 20 hours from a household outlet, but no mention has been made about the length of the actual extension cord you’ll need!