The the definition of light truck in the CAFE standard includes many SUVs and vans. Pickup trucks, SUVs, and vans made up around half of the passenger vehicles sold in recent years. The orange line shows the expected average fuel economy for the current mixture of trucks and cars. Keeping this mix of light trucks and cars will result in the average fuel economy only reaching 33.7 miles per gallon. Reaching the target of 35.5 mpg requires the fraction of new vehicles sold classified as light trucks to drop from one half to around one third. This is shown by the pink line.

From my estimate of the total number of cars and miles driven, I can estimate the gasoline burned, giving the CO₂ produced by all cars and light trucks on the road:

This shows the expected change with and without the new CAFE standard. For the base scenario (without the CAFE update), I included the expected change in the fraction of trucks sold. Notice that after the CAFE standard is constant, the expected CO₂ output resumes its climb. This is due to the predicted population increase, with the number of cars per capita remaining constant. The CAFE update will bring the expected CO₂ production from cars to below 2000 levels for nearly three decades, when population growth catches up with efficiency improvements.

Since I found the expected gasoline consumption with and without the CAFE update, it is easy to find the expected savings in CO₂ emissions:

Notes: The numbers from 2005 to 2010 are estimated based on 2004 levels. These years are estimated because accurate statistics are released a few years late. The scenarios not labled ‘current trucks’ include a decrease in the truck to car ratio starting with 1:1 in 2008 and reaching 1:2 in 2016. The data before 1979 isn’t as accurate as the 1979 to 2004 data, but the effect is negligible after the early ’80s due to the high turnover rate of miles driven.

Together, EPA and NHTSA estimate that the average cost increase for a model year 2016 vehicle due to the National Program will be less than $1,000…. over the lifetime of a model year 2016 vehicle, the consumer’s net savings could be more than $3,000. –EPA.

Here is a plot of historic US fuel economy along with the new standards. The historic data is based on the efficiency of cars sold each year and car survivability and miles driven by age. The plot shows all cars on the road each year, not just those sold that year. The future lines are directly from the new standards. Because the number of new cars sold is large, and new cars are driven more than older cars, the plot ignores the small hysteresis for future fuel economy. Data from 2005 to 2010 is estimated.

The various documents related to the ruling contain lots of interesting and useful information. For example, a good compilation of existing technologies that improve fuel economy, with an analysis of cost and efficiency changes. Some of these changes reduce manufacturing cost and improve fuel economy. I’ll probably use these reports frequently. They contains lots of information that I previously had gathered from many sources, as well as some I had calculated or planned to calculate.