File:Car Brand Quality in 1975 by Average of Overall Reliability Ratings.png

English: Chart of the 1975 Car Brand Quality Ratings by Overall Reliability

This rating of the car brands is an average of the overall reliability ratings of the brand's models. It provides a measure of how well a brand's models performed over the entire model-quality spectrum.

The formation of this measure of quality is based on the reliability charts of Consumer Reports.

To compute brand-quality ratings and assemble a brand-quality ranking using Consumer Reports' overall reliability ratings, a number is associated with each rating. A +1.0 is ascribed to a rating of Much Better Than Average, a 0.5 is ascribed to a rating of Better Than Average, a 0 to a rating of Average, a -0.5 to a rating of Worse Than Average, and a -1.0 to a rating of Much Worse Than Average. Then an average is taken over all of the brand's model years and models offering an overall reliability rating in the April 1975 issue of Consumer Reports. CR's 1975 overall reliability ratings are found in the Overall-Record row of its reliability charts.

For this measure of quality, the range is from -1.0 (the worst possible) to +1.0 (the best possible).

The quality ratings of the car brands by this set of computations are given in the bar graph above. Only those brands with at least 5 overall CR reliability ratings are included.

For a Google Knol that summarizes the changes in car brand and manufacturer ranking by this quality measure from 1990 to 2010, visit http://knol.google.com/k/james-bleeker/automobile-quality-by-car-brand-and/3o3u27f0whd6k/2?hd=ns# .