Hidden gems: identifying off-cycle fuel economy benefits

FUEL ECONOMY DETROIT: Conference addresses non-powertrain-related fuel economy improvements. By Michael Nash

The Department of Transportation’s (DOT’s) National Highway Traffic Safety Administration (NHTSA) and the US Environmental Protection Agency (EPA) issued rules in 2012 to ensure the automotive industry reduces greenhouse gas (GHG) emissions and improve fuel economy for light-duty vehicles from MY2017 through MY2025. The standards will reduce the carbon intensity of these vehicles by 40% from 2012 to 2025, raising fuel economy to up to 54.5mpg.

Discussing these targets at Fuel Economy Detroit by Automotive Megatrends, Kevin Green, Chief of the Corporate Average Fuel Economy (CAFE) Programme Office, US Department of Transportation (DOT) Volpe Centre, addressed the midterm evaluation of the standards.

“The Corporate Average Fuel Economy (CAFE) standards are final through to 2021,” he said.“NHTSA has to go through an entire new rulemaking beyond 2021. There will be this technical assessment released this year, and subsequent to that there will have to be a final rule for post-2021 standards. The outcome of it is prejudged at great risk.”

But many experts are eager to discuss the technologies that will be used to meet targets beyond 2021. Chris Nevers, Director of Climate Change and Fuel Economy at the Alliance of Automobile Manufacturers, observed: “We have concerns going beyond the 2021 standards because of the need and cost of hybridisation. Will people pay for it? Improvements in fuel economy are possible, it’s just a question of how much tech we need and how much it will cost.”

“Unlike the powertrain area, things that happen in the rest of the vehicle are often much harder to tease out. It’s a challenge we’ve faced for years, and we’re trying to make progress”

Although he referred to electrification, Nevers also believes that there will be some important improvements made by using technologies that produce “off-cycle benefits, which are not taken into account during the test cycle.” He believes that vehicle connectivity, for example, could play a vitally important role in improving vehicle fuel economy and reducing CO2 emissions.

Martin Richter, Vice President, Vehicle Systems, IAV Automotive, agreed with this idea. He believes that by using connectivity technologies that are available today, the fuel economy of passenger cars can be improved by up to 10%. He gave an example of having two vehicles travelling in tandem in order to dramatically reduce aerodynamic impact, connected through vehicle-to-vehicle (V2V) technology.

“Getting beyond that 10%, cars will have to speak to the infrastructure as well as each other,” he said. “We’d essentially have to eliminate the driver to get the complete 20% improvement in fuel economy, and enable features like coasting instead of stopping at red lights when it’s not necessary.”

Green also believes that connected car technologies could help the automotive industry hit fuel economy targets. However, these off-cycle benefits pose a problem for the DOT.

“I have an analytical role to support rulemaking, and a challenge we face is looking at the whole vehicle,” he said. “While we can examine vehicles and carry out detailed engineering studies, they’re expensive in terms of agency resources, so it’s hard to do comprehensively. Unlike the powertrain area, things that happen in the rest of the vehicle are often much harder to tease out. It’s a challenge we’ve faced for years, and we’re trying to make progress.”