openintro (version 2.4.0)

epa2021: Vehicle info from the EPA for 2021

Description

Details from the EPA.

Usage

epa2021

Format

A data frame with 1108 observations on the following 28 variables.

model_yr

a numeric vector

mfr_name

Manufacturer name.

division

Vehicle division.

carline

Vehicle line.

mfr_code

Manufacturer code.

model_type_index

Model type index.

engine_displacement

Engine displacement.

no_cylinders

Number of cylinders.

transmission_speed

Transmission speed.

city_mpg

City mileage.

hwy_mpg

Highway mileage.

comb_mpg

Combined mileage.

guzzler

Whether the car is considered a "guzzler" or not, a factor with levels N and Y.

air_aspir_method

Air aspiration method.

air_aspir_method_desc

Air aspiration method description.

transmission

Transmission type.

transmission_desc

Transmission type description.

no_gears

Number of gears.

trans_lockup

Whether transmission locks up, a factor with levels N and Y.

trans_creeper_gear

A factor with level N only.

drive_sys

Drive system, a factor with levels.

drive_desc

Drive system description.

fuel_usage

Fuel usage, a factor with levels.

fuel_usage_desc

Fuel usage description.

class

Class of car.

car_truck

Car or truck, a factor with levels car, 1, ??, 1.

release_date

Date of vehicle release.

fuel_cell

Whether the car has a fuel cell or not, a factor with levels N, NA.

See Also

epa2012

Examples

library(ggplot2)
library(dplyr)

# Variable descriptions
distinct(epa2021, air_aspir_method_desc, air_aspir_method)
distinct(epa2021, transmission_desc, transmission)
distinct(epa2021, drive_desc, drive_sys)
distinct(epa2021, fuel_usage_desc, fuel_usage)

# Guzzlers and their mileages
ggplot(epa2021, aes(x = city_mpg, y = hwy_mpg, color = guzzler)) +
  geom_point() +
  facet_wrap(~guzzler, ncol = 1)

# Compare to 2012
epa2021 %>%
  bind_rows(epa2012) %>%
  group_by(model_yr) %>%
  summarise(
    mean_city = mean(city_mpg),
    mean_hwy  = mean(hwy_mpg)
  )