This scatter plot shows simulated car data from 2019–2024, mapping engine size on the x-axis against combined fuel efficiency on the y-axis. Each circle represents a model-year combination, with circle area encoding horsepower and color distinguishing vehicle type. The visualization uses D3 v7 with SVG rendering, employing d3.scaleLinear for axes and d3.scaleOrdinal for categorical coloring. Interactive features include hover tooltips and click-to-select highlighting, implemented through d3.select and event listeners. Data comes from a CSV file loaded via d3.csv.