AAA's Tests Reveal Real-World Benefits of Automatic Stop-Start Technology
Research yields up to seven percent mpg improvement and CO2 reduction
ORLANDO, FL -- July 24, 2014: New research from AAA shows that automatic stop-start automotive technology delivers a significant fuel economy benefit. Test results indicated that automatic stop-start systems provide a five percent to seven percent improvement in fuel economy and reduction in carbon dioxide emissions compared with tests conducted on the same vehicle with the automatic stop-start system disabled.
AAA tested three vehicles equipped with automatic stop-start systems using the EPA's "urban" driving cycle. With the automatic stop-start system engaged, the vehicles delivered improved fuel economy of up to seven percent over tests with the automatic stop-start technology disengaged. Based on these findings, these systems can improve fuel economy, saving motorists up to $179 in annual fuel costs, based upon driving 15,000 miles a year in a vehicle that gets 20 mpg with fuel prices at $3.65 per gallon. "Up to seven percent improved fuel economy can mean a $179 annual fuel savings* for consumers," says Greg Brannon, Director of AAA's Automotive Engineering and Industry Relations team. "The technology requires only minor adjustment for motorists – automatic stop-start technology is simply applied to standard combustion engines."
Automatic stop-start systems turn off the engine when the vehicle is at a complete stop − such as in traffic or at a stoplight. When the driver releases the brake or the clutch, the engine starts and moves forward. While the engine is stopped, systems and gadgets run on power from the vehicle's battery. The feature most often deploys in city driving scenarios – versus highway operation – and may feel slightly different to motorists until they become accustomed to the automatic stop-start sensation. The benefits, however, will not be realized if the feature is turned off.
AAA put three automatic stop-start vehicles through the Environmental Protection Agency's "urban" cycle, which simulates a commuting trip covering 11.04 miles at an average speed of 21.2 miles-per-hour. The simulation is part urban driving – including frequent stops – and part highway driving. This test was selected to ensure that the stop-start systems had an opportunity to work as they would on a normal commute. A 2013 Ford Fusion, a 2014 Mercedes Benz CLS550 and a 2013 Chevrolet Malibu were tested. The AAA research was conducted with the Auto Club of Southern California's Automotive Research Center.
Automatic stop-start vehicles are still new to North American motorists, and drivers may not be familiar with the features and benefits of this technology. The U.S. Environmental Protection Agency and the National Highway Traffic Safety Administration have set standards to increase the Corporate Average Fuel Economy levels to 54.5 (approximately 40 window sticker) miles per gallon by 2025, giving automakers further incentive to escalate fuel-saving technologies. Navigant Research's 2013 automatic stop-start vehicles assessment projects that only 500,000 of the vehicles sold in the United States in 2013 included an automatic stop-start system, but that number could exceed seven million by 2022.
Additional information regarding AAA's tests of automatic stop-start vehicles is available on the AAA Newsroom. The study is part of AAA's Driving Fuel Efficiency series, which also includes the electric vehicle climate study and future fuel-economy studies.
AAA's Automotive Engineering team conducts proprietary research to better understand consumer implications of automotive technology, design and functionality.
As North America's largest motoring and leisure travel organization, AAA provides more than 54 million members with travel, insurance, financial and automotive-related services. Since its founding in 1902, the not-for-profit, fully tax-paying AAA has been a leader and advocate for the safety and security of all travelers. AAA clubs can be visited on the Internet at AAA.com.
About AAA's Driving Fuel Efficiency Series: From driving tips that increase gas mileage to the latest fuel-saving automotive technology, AAA's Driving Fuel Efficiency series will reveal research findings and expert advice to help motorists make educated driving decisions.
*Fuel savings are based on driving 15,000 miles a year in a vehicle that averages 20 mpg with fuel prices at $3.65 per gallon. These savings do not include other factors relative to ownership costs of vehicles equipped with automatic stop-start systems, such as potentially higher costs to replace the upgraded battery or starter typically used in these vehicles.