Energy Efficiency Fact Sheet

The document reports a decline in US automotive fuel economy from a 1987 peak of 22.1 mpg to approximately 21 mpg in 2005, attributed to increased vehicle weight, horsepower, and the popularity of SUVs and light trucks. It details advanced technologies for efficiency gains, including aerodynamics, low-rolling-resistance tires, hybrid drivetrains, weight reduction, and direct-injection stratified charge (DISC) engines. Additionally, it highlights the impact of basic maintenance—such as tire pressure, air filter replacement, and engine tuning—on fuel economy, and notes that increased efficiency reduces foreign oil dependence and greenhouse gas emissions.

• US automotive fuel economy peaked at 22.1 miles per gallon (mpg) in 1987 and fell to about 21 mpg by 2005. This decline is linked to vehicles becoming heavier and more powerful, as well as a shift toward sport utility vehicles (SUVs) and light trucks, which made up 50 percent of 2005 model year sales.
• Various advanced technologies can significantly increase fuel efficiency: aerodynamics can reduce drag (with the Toyota Prius having a drag coefficient of 0.26 compared to the H2 Hummer's 0.57), advanced tires can save 1.5 to 4.5 percent of gasoline consumption, and hybrid vehicles can double the efficiency of conventional cars, with plug-in hybrids reaching up to 250mpg.
• Reducing vehicle weight and utilizing specific engine types improve economy; the EPA states that every 10 percent of weight eliminated improves fuel economy by 7 percent. Direct-injection stratified charge (DISC) engines offer 15-20 percent higher fuel economy than typical gasoline engines.
• Routine maintenance provides measurable fuel savings: replacing a clogged air filter can improve mileage by up to 10 percent, and fixing a faulty oxygen sensor can improve it by as much as 40 percent. Proper tire inflation can improve economy by over 3 percent, leading to a US federal mandate that all vehicles sold after 2008 include in-car tire pressure monitors.

APA

Environmental and Energy Study Institute (2006). Energy Efficiency Fact Sheet. https://www.eesi.org/files/auto_efficiency_0506.pdf

Chicago

Environmental and Energy Study Institute. Energy Efficiency Fact Sheet. 2006. https://www.eesi.org/files/auto_efficiency_0506.pdf.

Wikipedia

{{cite report |author=Environmental and Energy Study Institute |title=Energy Efficiency Fact Sheet |date=May 2006 |url=https://www.eesi.org/files/auto_efficiency_0506.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{environmentalandenergystudyinstitute2006energy, author = {{Environmental and Energy Study Institute}}, title = {{Energy Efficiency Fact Sheet}}, institution = {Environmental and Energy Study Institute}, year = {2006}, month = may, url = {https://www.eesi.org/files/auto_efficiency_0506.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }