Overview
Column
Background
The mtcars dataset contains information on 32 car models from the
1970s.
Each row is one car model, with variables such as miles per gallon
(mpg),
horsepower (hp), weight (wt), number of cylinders (cyl), transmission
type (am),
and number of gears (gear).
This dashboard focuses on how fuel efficiency relates to engine power
and car
design. The target audience is a technical team that wants a quick
picture of
which cars combine better mileage with reasonable performance.
Scatterplot: fuel efficiency vs horsepower
Intrepretatiom:
Fuel efficiency falls steadily as horsepower increases. Cars with powerful engines around 200 horsepower or more cluster below 20 miles per gallon, while the most efficient cars sit under 120 horsepower. Manual transmission models tend to have slightly higher mileage than automatic models at similar horsepower, but the main pattern is the strong tradeoff between power and fuel economy.
Data source
The mtcars dataset comes from a 1974 Motor Trend magazine feature that compared fuel consumption and performance for a small sample of car models sold in the United States. Variables include miles per gallon, horsepower, weight, number of cylinders, gear count, and transmission type. The dataset is built into R and is used here only for teaching.
Design and accessibility: Color choices use palettes with good contrast and avoid red green pairs. Axis labels use clear wording and a base text size of 12 for readability. Both plots show simple encodings, without 3D effects or extra decoration, to limit visual load. The dashboard reports patterns in a small historical dataset and does not rate modern cars or real brands.
Column
Boxplot: fuel efficiency by number of cylinders
Interpretation : fuel efficiency by cylinders
Fuel efficiency is highest for cars with 4 cylinders. Their mpg values sit mostly in the mid to high 20s, with several models above 30 mpg. Cars with 6 cylinders have moderate mileage around 19 to 21 mpg. Cars with 8 cylinders have the lowest mileage, centered near 15 mpg. This pattern supports the standard tradeoff where larger engines with more cylinders draw more fuel.