1985 Auto Brand Quality Ratings and
by James Bleeker
Photograph of a 1984 Toyota
Corolla DX Liftback
at 550,601 Miles on 28 December 2010
|The exceptional reliability of the Toyota Corolla from model years 1979 to 1984
helped place the Toyota brand first among all brands in
two different quality measures.
This page provides two rankings of the brands of automobiles sold in North America
from model year 1979 to 1984. 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 1985 issue of Consumer Reports. The two sections providing the necessary statistics are CR's Some-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.
1985 Auto Brand Quality by Infrequency of Trouble-Prone Models
To form a brand-quality measure from the 1985 list of Some 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 1985 Some-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 1985 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 bar graph below. Only those brands with at least 5 overall CR reliability ratings are included.
Important Point: In 1985 and earlier, this brand quality measure may have substantial shortcomings at the upper end, possibly due to data shortage. While the rating for the Toyota brand likely reflects particularly great merit, as Toyota has 52 overall reliability ratings in CR's reliability charts and not one listing in the Some-Used-Cars-To-Avoid section, Chrysler's Plymouth and GM's GMC ranks may be very far from an accurate measure of quality, as the bar graphs based on the average of overall reliability ratings (below) suggests.
1985 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 1985 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 bar graphs below. Only those brands with at least 5 overall CR reliability ratings are included.
In the first graph, Chrysler's Plymouth brand places in the mid range
because the Mitsubishi-built, Plymouth-branded models lift the Plymouth
brand considerably. In the second graph, the Mitsubishi-built models are
removed from the Plymouth brand and placed in the Mitsubishi brand, with the
result that the Plymouth brand drops to third worst.
Summary and Analysis
Possibly the most interesting point displayed by the second pair of
graphs is that the fabled Mercedes-Benz brand, bearer of the
automotive-engineering excellence mantle for all of the 1960s, had fallen to
the Toyota brand by 1985, by average of CR's overall reliability ratings.
For a Google Knol that summarizes the changes in auto-brand and auto-manufacturer ranking by these quality measures from 1990 to 2010, click
AutoOnInfo.net: The auto-quality website with the
Open Directory Cool Site Award.