Why explore MPG?

Fuel economy is influenced by several vehicle characteristics, including:

• Vehicle weight
• Engine power
• Number of cylinders
• Transmission type

This presentation uses the built-in mtcars dataset to explore how these variables relate to miles per gallon (MPG).

The interactive visualization on the next slide was created using Plotly in R.

Interactive Plotly: Weight vs MPG

Try it: hover over points for vehicle details, zoom into a region, or use the legend to explore groups.

What does the plot suggest?

• Heavier cars generally achieve lower fuel economy.
• The correlation between weight and MPG is approximately -0.87.
• Manual-transmission cars average about 24.4 MPG.
• Automatic-transmission cars average about 17.1 MPG.
• Cars with more cylinders and higher horsepower tend to appear toward the heavier, lower-MPG region of the plot.

Because mtcars is an observational dataset, these relationships should be interpreted as associations rather than causal effects.

Takeaway

Interactive graphics make patterns easier to explore

Plotly allows the viewer to:

• inspect individual observations through hover labels,
• zoom and pan through the data,
• compare vehicle groups visually, and
• explore several variables in one interactive figure.

Created: October 27, 2026

Tool: R Markdown + knitr + Plotly