Assessment and correlation of customer and rater response to cold-start and warmup driveability
A program was conducted from January 14 through March 8, 1991, at Southwest Research Institute (SwRI) in San Antonio, Texas, to establish a relationship between demerits observed in CRC Cold-Start and Warmup Driveability assessments to customer satisfaction levels, and to determine which of several performance deficiencies associated with low volatility gasolines are most troublesome to customers during normal vehicle warmup. Customers used their vehicles in daily service, and a subset of the test fleet was evaluated by trained raters using the established CRC test procedure. There were 7,206 driveability performance assessments by customers which were correlated with 661 trained-rater cold-start driveability evaluations. One hundred sixty-seven SwRI employees participated in the program. Hesitation was the most widely observed problem and was the primary cause of dissatisfaction. The gasoline-ethanol and hydrocarbon-only fuel sets had distinctly different malfunction patterns. Hesitation was strongly associated with gasoline ethanol blends, while surge and stumble were strongly associated with hydrocarbon-only fuels. The current total weighted demerit (TWD) system was found to correlate poorly with customer satisfaction; however, customer observations of problems correlated no better with customer satisfaction. If TWD is to be an indicator of customer perception of driveability performance there should be uniform weighting of rater-observed malfunctions, and start-time should be assigned a greater weighting and a shorter grace period.
- Research Organization:
- Coordinating Research Council, Inc., Atlanta, GA (United States)
- OSTI ID:
- 5492161
- Report Number(s):
- AD-A-271775/9/XAB; CRC-585; CNN: DAAK70-89-C-0022
- Country of Publication:
- United States
- Language:
- English
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