This scatter plot visualization explores the relationship between fuel efficiency and horsepower across car models, using color to encode the region of origin and point size to represent vehicle weight. The plot is built with the Vega-Lite API, which registers with Vega and Vega-Lite libraries to render an SVG chart, while D3.js handles fetching and parsing the CSV data. Tooltips display vehicle names via the Vega Tooltip handler. The data originates from the UCI Machine Learning Repository’s Auto MPG dataset, loaded from a GitHub Gist.