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Lundi, 12 Septembre 2011 12:30

Cars Don't Waste Fuel. Drivers Waste Fuel

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Cars Don't Waste Fuel. Drivers Waste Fuel

Researchers at the University of California, Riverside’s Center for Environmental Research and Technology (CERT) are developing a new way of boosting fuel efficiency by as much as 30 percent without changing a car’s powertrain at all.

Their secret? Finding ways to change our behavior so we’re more attuned to maximizing their mileage while behind the wheel.

Sure, it may sound easier than reducing vehicle weight or adding batteries or developing some new engine technology, but it’s a daunting task. It’s relatively easy for engineers to tinker with a car, but even Sammy Hagar knows that people tend to resist efforts to change their behavior.

With a $1.2 million grant from the Department of Energy, the research team is in the very first stage of developing their study. Researcher Kanok Boriboonsomsin said he’s studying ways cars with network connectivity might offer a fuel-saving route on a GPS system, and how infotainment systems can provide real-time feedback on fuel economy without distracting or annoying drivers.

“When you get in the car, you have the vehicle recommend the route you could take based on traffic conditions on the route, and on the way if there’s anything wrong with your driving it may provide some feedback to you to adjust your driving behavior,” Boriboonsomsin said.

That’s key, because, as any hypermiler will tell you, the best way to increase fuel efficiency is to adjust the nut holding the steering wheel. Snarky, yes, but CERT’s research could help automakers help us improve our fuel economy without spending a dime on powertrain engineering. But first, the researchers at CERT have to find the best way to change driver behavior. That means creating a system that immediately emphasizes the benefits of efficient driving without creating a needless distraction or aggravation.

Cars Don't Waste Fuel. Drivers Waste Fuel

Ford's SmartGauge, shown here in the Lincoln MKZ Hybrid, provides real-time feedback on your driving style and fuel efficiency. Photo: Ford

The Nut Holding The Wheel

The team at CERT is hardly the first to try changing drivers’ habits to improve fuel economy. They were, however, the first to prove that drivers presented with real-time feedback about their fuel economy turned into instant hypermilers — reducing their fuel consumption by six percent on average by coasting to stoplights, laying off the gas while accelerating and upshifting as soon as possible.

It’s getting easier for drivers to know how their driving affects their gas mileage. Many modern internal combustion — and every EV and hybrid we’ve ever driven — features a dashboard display showing real-time and average fuel economy. Ford’s is among the best, encouraging drivers to embrace their inner hypermiler through an LCD display that turns lush and verdant when you’re cruising nicely at 55 but withers and dies during an impromptu stoplight drag race.

We’ve experienced this first-hand using the engaging and intuitive SmartGauge (shown above) in the Ford Fusion Hybrid and Lincoln MKZ Hybrid, and the very impressive energy management systems in the Nissan Leaf and Chevrolet Volt. In every case, the real-time info made us much more vigilant about our behavior and, yes, improved our fuel economy.

Fiat has gone so far as to give drivers extremely detailed report cards of how to improve their fuel economy. All Fiat 500s have Eco:Drive, a system that saves vehicle diagnostic data on a USB drive. Plug it into a computer, and the Eco:Drive software will generate a progress report that analyzes CO2 emissions and fuel consumption in terms of driving style. It’ll also compare you to all Fiat owners who use the program — about 66,000 people.

“Even though our cars are fuel efficient, we don’t want that to stop at the factory,” said Fiat brand manager Andrew Waterhouse. “We want people to continue to be mindful of how they’re driving and how to improve their driving.”

No Time Like The Present

Cliff Nass, a professor of psychology at Stanford University and author of The Man Who Lied To His Laptop, said there’s one problem with telling drivers how to improve their fuel economy after they’re out of the car: People learn best when they’re being coached in the moment. It’s called just-in-time learning, and it’s crucial to developing new skills.

“When you’re not driving, you’re not thinking about driving,” he said. “When you get this feedback and analysis, you’re not in the car. That’s one of the problems with these systems: When you can’t act on the problem right away, it’s not as effective.”

The only thing harder than teaching old drivers new tricks when they’re not driving is teaching old drivers new tricks while they are driving.

“When your car is moving, especially at reasonably high speeds or in cities where there’s lots of stop and go, that’s the wrong time to try to transmit messages to people. Their brains are elsewhere,” Nass said.

It’s a problem that Boriboonsomsin knows well.

“If a vehicle provides too much feedback, a driver could be overwhelmed,” he said, suggesting that audio feedback may be less distracting than visual prompts. Additionally, feedback must be nuanced and positive so it doesn’t become a source of irritation.

“The way we provide the feedback could turn off the driver if it’s too aggressive or commanding,” he said.

Don’t Tread On My Lead Foot

Cars that actively try to change a driver’s behavior inherently run the risk of making a fast enemy of the driver. Take, for example, Nissan’s Eco-Pedal, a system that makes it increasingly difficult to press the accelerator pedal in a way that would waste fuel. We once drove an M56 equipped with the feature, and immediately became exasperated with its nagging before turning it off 30 seconds later.

The Eco-Pedal certainly is effective at providing just-in-time learning, Nass said, but it’s useless if it’s always off.

“Not shockingly, people don’t like to be nagged,” he said. “The reward for not pressing the gas is it doesn’t nag you. Well, the sensation of a negative is not a positive. So people get angry and resentful and turn it off.”

Cars with “eco” modes are just as ineffective, said Nass, because they usually require drivers to flip a switch to engage them. They don’t provide any immediate benefit to the driver — people don’t think things through and realize saving gas saves them money — but they do give a noticeable drawback in the form of decreased throttle response. That’s why Fiat made its most fuel-efficient throttle mapping (and fastest upshifts in the automatic gearbox) the default mode. Drivers must “opt-in” to a more responsive, and less fuel-efficient, sport mode.

Even passive feedback systems, like fuel economy displays, may not be terribly effective if they force drivers to think in the abstract. Nass said the public good of “helping the environment,” as represented by an LCD pictogram of a growing vine, isn’t nearly so strong a motivator as saving money. For that reason, it might be far more effective if the LCD display showed dollar bills flying away as the driver laid on the gas.

“It’s an issue of people doing better understanding consequences for themselves,” he said.

Boriboonsomsin said the financial reward of fuel-friendly driving is a powerful motivator, as we so often see when fuel prices spike and sales of small cars increase.

“If gas is cheap, there’s not much incentive for them to change their behavior,” Boriboonsomsin said. But as fuel prices rise, “they may be more willing to change their driving behavior.”

Accentuate The Positive

Boriboonsomsin said a large aspect of driver feedback research will focus on connecting cars to intelligent transportation networks that determine the best routes for fuel economy. Such a system could help drivers avoid congested road — and therefore spare them from idling in gridlock — or direct them toward routes free of stop-and-go traffic. He calls this “completing the loop,” using real-time driving data to create useful strategies that keep drivers from wasting fuel.

Nass said that kind of feedback, the kind that encourages positive behavior such as, “make a right to avoid unnecessary idling at a stoplight,” is sorely missing in current dashboard displays and meddling gas pedals.

“The problem is, the negatives in these systems are much bigger than the positives, and that’s a mistake,” he said.

Another powerful motivator? Getting fired for lead-footing or getting a bonus for saving fuel. That’s why fleets are especially interested in changing driver behavior to reduce fuel bills.

“In a fleet system, you have someone else who can penalize you or reward you,” said Nass.

He said a fleet driver’s corollary to the abstract goal of “saving the environment” may be helping the company’s share price, which has little effect on the individual driver. However, getting a bonus for having the lowest overall fuel consumption directly impacts the individual.

“The key in fleet is there are direct consequences,” he said.

Driver’s Ed

Cars already can tell us how to save fuel, but they can’t effectively convince us to change the way we drive with a happy tree, a report card or a dashboard display.

They may, however, help us save fuel with a smartphone app that can detect stoplights. The SignalGuru project, from researchers at MIT and Princeton, uses a smartphone camera and traffic signal data to tell drivers whether they should start slowing down to avoid waiting at an upcoming traffic light. In trials on the streets of Cambridge and Singapore, drivers using SignalGuru have been able to cut fuel consumption by 20 percent.

Thanks to researchers like those at MIT, Princeton and CERT, the cars we drive in the not-so-distant future may become better teachers, subtly guiding us to fuel-efficient driving patterns. Connected with an intelligent transit network, they’ll help us save money, showing us more fuel-efficient ways to get to work, gently reminding us to lay off the gas pedal and allowing us to make decisions on engine programming based on our own historical driving patterns.

And instead of people redesigning cars, cars of the future will change the people who drive them.

Photo: The Honda CR-Z hybrid, being driven somewhat less than fuel-efficiently. Jim Merithew/


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