“Stop-start is a clever technology, but it has lots of ramifications,” said Francis Fodale, Director of Powertrain Integration, NAFTA Powertrain Engineering at Fiat-Chrysler Group LLC. Fodale was the moderator for an FEV Powertrain Innovation Forum Tuesday afternoon SAE 2013 World Congress session titled "Stop-Start is Coming to North America, But Will it Stop or Start Sales?"
U.S. consumers don’t have a lot of firsthand experience with the technology given that stop-start’s market share was a paltry 1% in 2012, compared to Europe’s double-digit percentage.
Scott Dahl, Regional President of Starters Motors & Generators Division, NA for Robert Bosch LLC, said stop-start’s success in North America is “dependent on nearly transparent system operation to the end user.”
Robert Martin, Director of the Engine Electric Group for Denso International America Inc., showed session attendees a video clip of persons expressing unfavorable views of the technology—including concerns about the product’s refinement—as well as persons expressing favorable opinions about stop-start. “Attitudes and perceptions were just all over the map,” Martin said of his talks with consumers.
Michel Forissier, R&D & Product Marketing Director for Valeo Powertrain Systems, said there are issues that need to be overcome, regardless of the type of stop-start system. For example, the loss of air conditioning during engine-off time is problematic. But solutions exist, namely electric compressors and/or air-conditioning evaporators with cold storage.
The unwanted ‘creep’ at a traffic light is another issue, but the possible fixes include an oil pressure buffer in the automatic transmission. “There are some countermeasures,” Forissier said.
All of the various stop-start systems offer a fuel-savings benefit.
For instance, a belt starter generator (BSG) version provides a fuel savings today “between 5% and 6% on the NEDC (New European Driving Cycle),” according to Forissier. A ReStarter application—a system that’s been reinforced for a higher number of cranks and can only recrank when the vehicle is stopped and the engine is stalled—provides a fuel savings around 3% to 4% on NEDC, according to Forissier.
Mark Rakoski, Executive Director, Sales & Engineering, at Mitsubishi Electric Automotive America, said the industry has an assortment of viable solutions for stop-start technology.
“The lower-cost solutions provide the best cost-to-benefit ratio. However, stop-start is not completely ‘seamless’ to the customer. And the lower-cost solutions are even less ‘seamless’ than the higher-cost solutions,” said Rakoski.
How many U.S. vehicles are equipped with stop-start in the future may greatly depend on how well the end consumer understands the technology’s operational nuances.
“As an industry, we must find ways to educate consumers and the government on the capabilities of the technology to ensure that stop-start is accepted short and long term,” Rakoski said.
Dahl also stressed the importance of the end consumer being educated and informed on how and when the system operates, “so if the engine suddenly doesn’t shut off when it normally does they won’t think there’s something wrong.”
Two keys to getting consumers to understand stop-start technology are well-informed salespeople at dealerships and vehicles having relevant human-machine interfaces to inform the driver of stop-start activities, according to Dahl.
Drivers could also benefit from an educational campaign on stop-start technology that mirrors what was done with electronic stability control.
“We as an automotive industry—suppliers and OEs—worked together on electronic stability control. There was an educational alliance formed on that aspect many years ago. And the sole purpose was to have an unbiased approach to educating the end consumer of what is the technology, what are the benefits, and how does it work,” said Dahl.