A new Q&A feature by Environmental Engineer Vern Novstrup.


 Dear GreenLight:

My husband and I are considering buying our first new car. We would like to by a vehicle that both meets our needs and is good for the environment. When we talk to the various salesmen, we often either get no answers or conflicting answers. Do you have any specific recommendations regarding finding the most environmentally friendly vehicle.

-- D.J.

Dear D.J:

I doubt cars could ever be considered to be environmentally friendly. However, they are becoming significantly better. Today's cars emit less smog, use less fuel and are more recyclable then ever. However, there is a wide variation between models. By choosing smartly you can not only help the environment; in most cases, you will also save money.

The first issue to consider when buying a vehicle is the minimum features that will meet your needs. For example, if you intend to use the vehicle for commuting to work you may want to limit your search to compact models. On the other hand, if you're a soccer mom or dad you may need to consider something considerably larger, such as a station wagon or minivan.

After you have decided which class of car best fits your needs, you should look for the vehicle in that class which gets the best possible gas mileage and/or emits the fewest pollutants. The job of determining which vehicle gets the best mileage is made easier by federal standards that require that each new vehicle carry a label showing fuel economy. Additionally, EPA maintains a web site at that lists estimated fuel mileage for all available vehicles.

Vehicles sold in California are required to carry a label showing how much they pollute relative to emission standards. Within any given class of vehicles, a lower number indicates that the vehicle pollutes less. However, keep in mind you should not use the Emissions label to compare cars to SUVs, because SUVs are allowed to pollute more. Additionally, the California Air Resources Board maintains a web site at that provides a list listing of low emission vehicles.

By considering both fuel economy and air emissions in your vehicle selection, you will be rewarded with lower fuel costs and a better chance of passing that pesky smog checks. Although is sounds insignificant, by improving fuel economy by just 3 mpg you may be able to save up to $150 per year. Although the benefits of lower air emissions are more intangible, clean is good in smoggy Southern California.

Dear GreenLight: I recently moved to San Diego from the Midwest. I've noticed many of the weather sections in the local papers contain an "Air Quality Index" or AQI. How is the index calculated? What does it mean? Is the air in Southern California really that bad?

-- M.R.

Dear M.R.:

First, let me welcome you to Southern California. Hopefully, in living here you will be part of the solution to our environmental challenges by living in a sustainable way.

The AQI is a simplified method of providing information to the public on air pollution for major contaminants (ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide). A detailed description of the AQI may be found at the EPA web site The key point to remember is that if the AQI exceeds 100, air quality is considered "unhealthy for sensitive groups" and if the AQI exceeds 150, air is considered "unhealthy" for everyone. If possible, avoid exercising outdoors if the AQI exceeds 100, or try to exercise early in the day before smog starts forming. Also, you can help to improve air quality by limiting your driving on days in which forecasts indicate poor air quality.

The air quality in So-Cal has improved dramatically in the last few years. However, we will need to do a lot more to get the air quality that could be called good. Currently, in most areas on most days, the air quality is acceptable. However, we still get a few days per year in which the air quality is unhealthy. The major problem in So-Cal is emissions of volatile organic compounds such as unburned gasoline and nitrous oxides that react in sunlight to form ozone, usually in inland areas. Exposure to high ozone levels can cause eye irritation, irritation of the lungs, chest pains, cough, shortness of breath, nausea and headache. In most cases symptoms are minor but, in a few cases, medical treatment may become necessary.

Responses are prepared by Mr. Vern Novstrup, an Environmental Engineer. Comments or questions for future columns may be directed email to