Date of Award

Spring 5-1-2019

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

College of Technology

Abstract

Today, automotive industries and their consumers are demanding more information on electric vehicles in response to the ongoing transportation transition from conventional to electric vehicles (EVs), the problems of greenhouse gas emissions from conventional vehicles (CVs) and fossil fuel usage, and interests in green energy production and the overall environmental health of this world. This study identified four variables - fuel economy (FE), annual fuel cost (AFC), maintenance frequency (f), and maintenance intensity (I) - and used comparative statistical quality assessment and failure mode and effect analysis (FMEA), a reliability management tool, for data analysis comparing conventional and electric vehicles. The research examined samples of 1,028 CVs and 282 EVs from 2016 to 2018 models for FE and AFC assessments, and 23 CVs with 65 maintenance events and 119 EVs with 348 maintenance events from 2000 to 2016 for maintenance frequency and intensity assessments. The study used Minitab 18 with two-sample t-tests at the 95% confidence level for hypothesis testing. The results found that the means for FE of CVs were not significantly different between 2016 and 2017, or between 2017 and 2018 models. For EVs, the means for FE were significantly different between 2016 and 2017 i.e. 2017 FE was better than 2016, but the means for FE of 2017 and 2018 models were not significantly different. In addition, the mean FE of EVs was overall 74.19% higher than that of CVs. Moreover, the mean AFC of EVs was significantly i.e. 47.68% less than that of CVs, revealing lower annual fuel expenses for EVs. v The mean frequency and intensity of maintenance of EVs were found to be approximately the same as those of CVs. The study also found that the total number of failure processes was lowest in battery electric vehicles (BEVs) and highest in hybrid electric vehicles (HEVs). Plug-in electric vehicles (PHEVs) verified the highest risk and CVs the lowest risk in vehicle systems based on risk priority number (RPN), which was calculated from the product of severity (SEV), occurrence (OCC), and detection (DET). The maintenance cost of EVs was found to be 1.2359% of manufacturer suggested retail price (MSRP) per year, which was 4.7117% less than that of CVs for 10 years. The study results confirmed that EVs are generally better in FE with less expensive annual fuel cost and maintenance cost relative to MSRP than CVs. The results also indicate that the FE of EVs improved from 2016 to 2017 but remained relatively constant from 2017 to 2018. Consumers of both EVs and CVs therefore have to do vehicle maintenance about the same number of times per year. Among EVs, the researcher would recommend choosing BEVs over HEVs or PHEVs. Future researchers can refer to this study to inform and improve further research, vehicle designs, management of different vehicle systems, profitability of manufacturers and consumers, and the advancement of the vehicle industry. In addition, consumers can adopt the miles-per-dollar (MPD) unit conversion introduced in this study in order to calculate fuel-and-distance-related costs from miles-per-gallon (MPG) and miles-per-gallon-equivalent (MPGe) values.

Download

Share

COinS