newFitOwner

I just picked up a Fit. Getting use to the stick shift after countless years of driving stick on a 97 Tercel. Also getting use to the additional feedback from the tacometer and fuel efficiency monitor. I'm using 2000rpm as the threshold for shifting down, and 3000 rpm as the threshold for shifting up. I'm a bit puzzled by the fuel efficiency monitor. Before I had one, I would simply floor the accelerator on the Tercel. Of course, it responded in the way that any subcompact would, by ignoring the flooring and speeding up in its own good time. Because of this casual response, I assumed that nothing bad was happening -- I assumed that the engine was operating in exactly the same way as it does at the point in the pressing down of the gas pedal where it stops responding anymore.

Now that I have a fuel efficiency monitor, it shows that this is far from true. It shows the efficiency dropping markedly as I continue pressing the accelerator beyond the point at which the engine stops responding anymore. How is this possible, I thought -- the sound of the engine isn't changing at all! I did some web surfing and the general explanation seems to be that the algorithms controlling the fuel injection responds to the flooring by dumping tons of fuel into the combustion chamber, even though it doesn't actually help. Can anyone confirm with any confidence if this accurately reflects the "ground truth" with the Fit? If so, it means I can't just blindly floor it and rely on the irresponsiveness of the acceleration as a natural limiting mechanism on harmfully overdoing the acceleration.

Up until the time I found that (proposed?) explanation on the web, I assumed that that dramatic drop in fuel efficiency (in the absence of any change in acceleration) was because of simplistic monitoring algorithms. That is, the efficiency is shown to drop simply because in general, it is unproductive to floor the accelerator. But now I wonder if in fact the distance per gallone/litre is actually being monitored accurately moment by moment.

claymore

The Fit just does not "dump fuel into the combustion chamber". The air fuel mixture is controlled by the ECM and it samples the conditions several times a second so the mixture is just right to Honda specs.

You simply can't "feel" the increase in acceleration but it's there. Time for a tuneup on your "buttdyno".

The monitor is correct anytime you move the throttle open there is a corresponding drop in MPG because the ECM is injecting more fuel it's not hard to figure out.

10psiLsEf2

If your talking about an ECO mode or FUEL SAVER mode.

Its all bullshit. Its wired into your throttle position sensor. Once the tps sees a certain amount of votageit shuts off eco mode.