Chapters 7 & 8 of the Low Carbon Diet focus on ways to reduce your personal CO2 output related to driving a car - or, in our case, driving two cars between 15,000 and 18,000 miles a year each.

First, you need to know how much and for what purposes you are driving. The author suggests keeping a driving log in each car for a week, then evaluating your car usage to see where you can be more efficient. I'll give you a couple of examples:

1. I get my hair cut at a salon that is near our grocery store. For my August appointment, Tom dropped me off there, then went and did the grocery shopping while I had my hair cut. The time worked out about right.

2. Our neighbor Meg & I go to the same church in Woodstock, about 15 miles away. On Sundays when one or the other of us is going (we are both irregular attendees), we make a point of calling the other to see if she wants to carpool.

In addition to combining trips and carpooling, the book offers other suggestions for reducing the miles you drive.

The carbon-cutting tip I really like is the one about tele-commuting. If you can figure out how to work from home one day a week - and not drive at all that day - just think how much gas you would save. That would be at least 20% of your work-related vehicle miles!

The book has a handy table that helps you calculate the approximate amount of CO2 your driving releases each year. In our case, 2 cars that get about 40 mpg (one averages 38-40 and the other 40-43) driven about 17,000 miles a year, results in about 17,000 pounds of CO2 released annually. If we eliminated 20% of those miles, we would reduce our CO2 output by 3500 pounds a year!

But, even without cutting miles driven, we can all improve fuel efficiency in the way we drive. We've discussed some of this before:

- drive the speed limit, and maintain a steady speed (use cruise control if you have it for highway driving, and when that line of cars forms behind you because you are driving the speed limit, think of it as if you are leading a parade of fuel efficincy!) 45-55 mpg is the most fuel efficient speed for most cars. Driving 75 mpg uses about 20-30% more fuel than driving 55!

- turn the engine off when you are stopped for more than 10 seconds. Like at the bank drive through, or the drive-up ATM, or even the fast-food window. Let's be realistic, they may be fast, but are they 10 seconds fast? It is a myth that you use more fuel to restart the car than you save by not idling. Think of it this way: when your car is not moving and the engine is running, you are getting ZERO miles to the gallon!

Just driving smarter can improve fuel efficiency by 10% or more! Hey, it's your $3.29 a gallon, you can spend it however you want!