1990 Auto Brand Quality Ratings and Rankings
by James Bleeker

Content Summary

This page provides two rankings of the brands of automobiles sold in North America from model year 1984 to 1989. Each ranking employs a different method of computation.

The statistics used in the computations for rating and ranking the brands are those found within the April 1990 issue of Consumer Reports. The two sections providing the necessary statistics are CR's Used-Cars-To-Avoid list and its reliability charts. Reliability is defined by the magazine as the infrequency of serious problems, which it measures annually by a subscriber survey.

The first ranking of the car brands is based on each brand's infrequency of trouble-prone models. This ranking provides a measure of how well each brand's models successfully avoided the bottom end of the model-quality spectrum.

The second ranking of the car brands is based on the average of the overall reliability ratings of each brand's models. The second ranking provides a measure of how well a brand's models performed over the entire model-quality spectrum.

1990 Auto Brand Quality by Infrequency of Trouble-Prone Models

To form a brand-quality measure from the 1990 list of Used Cars To Avoid, the first step is to count each brand's entries on the list. Each model year of each model is treated as a separate entry.

Next, as the number of automobile models sold under a brand name varies greatly from brand to brand, it is necessary to take account of the fact that a brand with more models has a greater opportunity to have more model years of low quality. To compensate for a possibly inflated, or deflated, frequency of trouble-prone model years within a brand, as well as a variability in model data sufficiency, the number of a brand's entries in CR's 1990 Used-Cars-To-Avoid list is divided by the total number of overall reliability ratings for the brand found in the reliability charts of the same issue of Consumer Reports. The overall reliability ratings are found in the Trouble-Index row of the 1990 reliability charts.

By the method of computation, this quality measure begins with 0 and may run to a value some greater than 1. The value of 0 is the highest quality rating attainable by a brand and is achieved only when a brand has no entry on the Used-Cars-To-Avoid list.

The quality ranking of the car brands by the foregoing computations, together with their quality ratings, is given in the first bar graph below. Only those brands with at least 5 overall CR reliability ratings are included.

1990 Auto Brand Quality by the Average of Overall Reliability Ratings

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 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. CR's 1990 overall reliability ratings are found in the Trouble-Index 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 ranking of the car brands by this set of computations, together with their quality ratings, is given in the second bar graph below. Only those brands with at least 5 overall CR reliability ratings are included.

The Bar Graphs of 1990 Brand Quality

In both of the graphs that follow, the order of the car brands is with the best on top.

When two or more auto brands have no entry in CR's list of Used Cars To Avoid, the brands are listed in descending order of number of overall reliability ratings (a brand with a greater number of overall reliability ratings appears above a brand with fewer ratings), as those brands with a greater number of ratings would have a greater opportunity for a trouble-prone model year to be found.

Summary and Analysis

Likely the most interesting point displayed by the pair of bar graphs is found in the second graph. By overall reliability, all of the automobile brands in the top half were Japanese and European, by the location of the corporate headquarters of the companies owning the brands; not one was North American.

For a Google Knol that summarizes the changes in auto-brand and auto-manufacturer ranking by these quality measures from 1990 to 2010, click Go.

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