MTCARS MPG Explorer

title: MTCARS MPG Explorer author: Isi date: April 24, 2026

Problem and Solution

MTCARS MPG Explorer is a small interactive Shiny app built for the Coursera course Developing Data Products.

Its goal is to turn the classic mtcars dataset into a simple tool for exploring fuel efficiency.

The app lets users:

• filter cars by horsepower
• compare automatic and manual transmission groups
• focus on selected gear counts
• visualize the relationship between car weight and fuel economy

Why the App Is Useful

Fuel economy is not driven by one variable alone.

Instead of reading a static table, users can interactively explore how vehicle weight, horsepower, gears, and transmission type influence miles per gallon.

This makes the app useful for:

• learning exploratory data analysis with a familiar dataset
• understanding simple relationships in automotive performance data
• seeing how filters change both plots and summary statistics in real time

Reproducible Evidence

The app uses the built-in mtcars dataset, so it is fully reproducible without external downloads.

The deployed Shiny app is available here:

https://img-mgt.shinyapps.io/mtcars-mpg-explorer/

{r, echo=FALSE} summary(mtcars[, c("mpg", "hp", "wt", "gear")])

Embedded R Code Example

One of the clearest patterns in mtcars is that heavier cars tend to have lower fuel economy.

{r, echo=FALSE} plot( mtcars$wt, mtcars$mpg, pch = 19, col = "#2C7FB8", xlab = "Weight (1000 lbs)", ylab = "Miles per gallon", main = "Weight and fuel economy in mtcars" ) abline(lm(mpg ~ wt, data = mtcars), col = "#D95F0E", lwd = 2)

The regression line highlights the negative association between weight and MPG, which users can inspect interactively inside the app with filters and live summaries.