It’s midday on Grant Street in Chinatown and passersby are turning their heads to gawk at Fire Engine 13. Firefighter Truc Nguyen smoothly guides his ride from Commerce Street to Grant beneath low-hanging red lamps. The tight corridor makes the engine look huge, but the cherry-red vehicle, one of eight smaller fire engines the San Francisco Fire Department deployed late last year, is uniquely suited to handling The City’s increasingly narrow streets. The smaller vehicles — nicknamed “Vision Zero” fire engines after The City’s initiative seeking to reduce traffic collision deaths to zero by 2024 — could also go a long way toward reducing tensions between the department and pedestrian and bicycle advocates over street safety improvements.