Model Years 1980 & Older

The highlighted region of this graph represents cars with a model year postdating 1980. It can be shown that for these newer cars, a higher percentage receive "GOOD" or readings after passing by the Smart Sign in comparison to older cars made before 1980. This is widely due to the introduction of pollution control devices such as oxygen sensors and catalytic converters.

It is unusual for a newer car to receive either "FAIR" or "POOR" readings when driving by the smart sign. A well maintained newer car should rarely receive a "FAIR" rating from the Smart Sign.

However, no car should ever receive a "POOR" reading from the Smart Sign.

If you received a "POOR" reading after driving by the Smart Sign, then you car is an excessive polluter and needs to be checked out.

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This site was last updated October 3, 2003