SPL

I think the 10 second averaging you mention is for the digital readout in the NAV display when it is set to the "consumption" mode. The bars update themselves every minute but the digital value in the lower right corner updates about every 10 seconds. The analog display which takes the place of the tachometer updates instantaneously.

 

Beyond the basic things that you can control to increase mileage (running your AC instead of rolling down windows, keeping your tires inflated, etc), your personal driving habits are not only the most important factor in your mileage, but the one that you have the most control over. In my own experience, I realized right off the bat that by looking at the mileage gauge I could adjust by driving habits to increase the mileage from 35 on average to over 40 MPG on average -- and use 15% less gas. This is easy to do when driving familiar roads since I could develop a memory based on experience of where and how to drive to get optimal mileage. It is a little more difficult when driving in unfamiliar terrain, which is where some sort of indicators would be nice (even a simple tach gauge would help). In such situations, I find my average mileage actually falls below 35. Nissan announced a new technology called the Eco Pedal, which takes this concept one step further by providing visual and force feedback when encountering "unfavorable" acceleration. A little "ECON" light glows green when accelerating favorably, and starts to flash prior to unfavorable acceleration (which it knows based on the transmission of the particular vehicle), then glows red after unfavorable conditions are met. In addition, the gas pedal actually provides force feedback (increased resistance) when you get near unfavorable acceleration. Nissan estimates this will result in 5-10% increase in efficiency...not because of any technology in the drivetrain but because of actionable information provided to the driver in a meaningful way, much like the scanner described in the OP. The increases would likely be even greater in a hybrid since much of the savings during acceleration would net a greater mpg since hybrids get disproportionately better mileage at lower speeds than the gas engines estimated in the study. Interestingly, I've noticed the TCH provides some slight force feedback right before it switches over from all-electric to gas, which that alone helps me achieve increased mileage along with the mileage gauge. It would be great if we could get a green, yellow, red light hooked up to whatever factors (tach, etc) result in increased mileage for the TCH. A little science project for the electronically and mechanically inclined

 

GreenRedTCH — No, I'm pretty sure that what I saw was in relation to the instantaneous FC/FE gauge on the dash, but I can't locate it now. (I don't have NAV myself anyway.) The fact that the instantaneous FC/FE gauge uses averaging over a time period of a few seconds does not mean that it doesn't start reacting immediately; only that the needle does not reach its final value until some seconds later. If it didn't do some averaging, it would be fluctuating all over the show from moment to moment. I agree that its time constant can't be 10 or even 5 seconds — it seems closer to maybe 3 s (guess).

Stan