The curriculum, Hot Wheels Speedometry (Mattel, El Segundo, CA, USA), was designed to align with the Next Generation Science Standards for science and the Common Core State Standards for mathematics. Our objective was to develop, implement, and evaluate the impact of this integrated science, technology, engineering, and mathematics (STEM) curriculum on students' knowledge, interest, and engagement. The authors conducted the study in a district where students were predominantly from communities under-represented in STEM fields. The findings indicate that student individual interest developed. Furthermore, students demonstrated affective, behavioral, and cognitive engagement along their progression of interest development. The study shows promise for the development of interest and engagement in under-represented groups through the use of an integrated STEM curriculum.