This bubble chart visualizes the relationship between average horsepower, torque, and highway MPG for 31 car makes, with each bubble positioned along x- and y-axes and sized by fuel efficiency. Built with D3 v7, it uses `d3.scaleLinear` for axes and bubble radius, a color scale based on `d3.interpolateTurbo`, and a legend for MPG values and car make. Hovering over a circle triggers a custom tooltip, while the SVG output is rendered with axes, labels, and legend circles. Data comes from the bundled bubblechart.csv file.