Going light on the throttle seems like such a no-brainer when it comes to increasing any vehicle’s fuel economy. As you may know, we’re big proponents of easy, gentle driving techniques, and we talk a lot about driving lightly and easing up on the “go pedal” in our Thrifty–Drive techniques and top 20 efficient driving tips articles. But it’s not always second nature: While driving in congested traffic or watching for street signs and exit ramps on highways unknown, one’s attention to driving style can fly right out the window. In response to the stress, pushing harder on the accelerator often happens unconsciously, and that equates into using more fuel than necessary. There must be a better way, a way to maintain economical driving practices without having to always be thinking about it, right? Enter Nissan’s ECO Pedal.
How Does ECO Pedal Work?
ECO Pedal is a Nissan-developed electromechanical feedback system incorporated into a vehicle’s gas pedal/accelerator control system. Each time the driver steps on the pedal, a pressure sensor determines how much force is being applied. This value is fed to the computer and compared to numerous additional operational parameters (vehicle speed, engine speed, load, transmission operation efficiency and fuel flow rate). From this data, the computer determines the optimal acceleration rate, and if the driver is pushing harder than necessary, the ECO Pedal applies an appropriate amount of push-back (mechanical counter pressure) to encourage the driver to ease-up on the pedal. In addition, the system displays an ECO light, in varying modes of illumination (depending on prevailing driving conditions) in the instrument panel. When enabled, the system works automatically, but it can be turned off if the driver wishes. The technology, currently slated for 2009 model year introduction, is expected to return up to 10 percent fuel economy improvements.
Vehicle’s engine is idling, driver’s foot off the pedal and ECO light off.
Driver pushes gently on throttle. ECO light glows solid green signaling economical operation. If the driver begins to push harder, to accelerate faster, the ECO Pedal pushes back gently and the ECO light begins to blink green signaling potential unfavorable fuel consumption.
Vehicle has reached cruising speed and as the driver lessens pressure on the throttle, ECO Pedal reduces feedback and the ECO light remains solid glowing green.
ECO Pedal system operates (and returns feedback) similarly to initial acceleration parameters, except that it provides feedback with greater emphasis on vehicles dynamics. Inefficiencies encountered, and energy required, to overcome the inertia and drag of setting in motion a heavy stationary vehicle differ greatly from the parasitic losses incurred by transmissions and engines in keeping the moving vehicle at speed.
Driver continues to press heavily on the throttle, ignoring push back from ECO Pedal. As the engine surges to increase speed, fuel flows at a high rate and the ECO light flashes bright orange signaling excessive fuel consumption. The system will allow the driver to accelerate as briskly as he/she wishes, but gives ample warning of the subsequent fuel penalty.
While the technology does seem to be a bit “gadgety,” and it’ll probably take several revisions to perfect, it’s a sound idea. Oh sure, there’ll be drivers who take umbrage at their car’s computer “telling” them how to drive, but remember that the system can be disabled at the driver's discretion. Don’t like that overprotective “nanny” pedal or that irksome ECO light blinking in your face? Turn ‘em off. But if you’re serious about achieving great fuel mileage, how can you go wrong here. The combination of manual and visual prompts is sure to make things easier. Most currently produced vehicles (especially hybrids) offer some kind of visual feedback (ECO gauges, power meters and fuel usage displays). We’ve test driven dozens and dozens of cars over the years, and we can’t imagine not having these “game gauges” at our disposal, ever egging us on towards better and better fuel economy.
This new technology just takes it all to the next logical level. Imagine that long trip: You, Joe/Jane Driver, are cruising along, jamming to tunes on your 350-watt, 8-speaker sound system and unconsciously stabbing at the throttle with every crescendo. Or maybe you’re traveling unknown highways, dodging traffic and watching for the nearest rest stop. Your attention certainly is not on foot-to-pedal pressure. You surge with traffic without really being aware of what your foot is doing. ECO Pedal push-back is that gentle nudge to stay present and attentive. And who knows, ECO Pedal could even end up acting every bit the safety device as well, keeping driver attention focused on the task at hand. (Yes, that would be the driving.) And while a lot of fuel saving gadgets don’t end up working, this one seems like it really will. All in all, we think ECO Pedal looks and sounds pretty good—after all, saving fuel is always a good thing, right?