<![CDATA[Vocational education is expected to build applied technical mastery and an entrepreneurial mindset together, yet the two are usually cultivated separately. HCS research has concentrated on engine performance without examining pedagogical value; teaching factory research has relied on routine, low-technology products; and no study has examined how an applied automotive product can build student competence and teacherpreneur character together. This study addressed that gap by developing a dual Hydrocarbon Crack System (HCS) fuel-saving prototype as part of a teaching factory learning strategy, then evaluating its effect on students' cognitive achievement, practical skills, and teacherpreneur character. A research and development approach following Borg and Gall's model guided product design, fabrication, and expert validation, followed by a quasi-experimental, nonequivalent control-group field trial across one semester in four Central Java vocational high schools, in partnership with PT Triangle Motorindo. Expert validation rated the finished prototype very good, and performance testing on the industrial partner's vehicle showed a meaningful, consistent reduction in fuel consumption and in carbon monoxide and hydrocarbon emissions within the tested operating range. Students taught with the product substantially outperformed a conventionally taught comparison group in cognitive achievement, practical skills, and all four teacherpreneur indicators, with the advantage holding consistently across schools of differing workshop provision. The findings suggest that a single, technologically substantive product can strengthen school industry collaboration, build student competence, and cultivate entrepreneurial character at once, offering vocational schools and their industry partners a concrete model for linking applied research to classroom practice.]]>
