This bubble chart visualizes the correlation between average horsepower, torque, and highway MPG across 31 car makes. Each circle is positioned by horsepower (x-axis) and torque (y-axis), with its size scaled to highway MPG and color representing the manufacturer. The example demonstrates D3 v7 data loading via `d3.csv`, linear scales for axes, ordinal color scaling, and interactive tooltips on mouseover. It uses SVG rendering with `join` for data binding and includes a dual legend for bubble size and categorical colors.