Hi Everyone.

I just bought a Silver '10 fit last Sunday, first time I've bought a brand new car. I am confused about the instant fuel economy meter. The range is 0 - 40 - 80 iirc, and the meter doesn't seem to settle down on any single value. For example, when I accelerate, the fuel meter might go all the way up to 80, then come back down, when I am idle, it reads '0', and when I am cruising along at constant speed it goes up and down, and not in response to engine load. Any idea what is going on?

I haven't actually used a tank yet, so I don't know how the 'average mpg' compares to actual, but it seems like it is fairly accurate with around 30mpg in the city. It calculates the average right, but maybe I just don't understand the instant very well?

 

Its an "instant" MPG gauge... literally.

Your mpg changes from one second to the next, or more specifically from one instance to the next, that's why it changes, it's not an average over time (other than "instant").

The only time it should "settle" is when everything is constant. Stopped is constant, cruising on flat roads is constant. Accelerating and braking is not constant (in speed)... So the instant mpg will change.

 

It's strange, in metric system, it's 0l/100km-10-20. And at idle it reads 0 (if you move slowly in neutral it reads "real" instant mpg though), and at WOT 20l/100. Maybe that because it's inverted with the mpg, it's less accurate.

 

The Instant MPG meter is very sensitive. The accelerator pedal is very light (unless you add a spring to stiffen it). This can make it hard to tell when your foot is pressing down. I use the Instant meter to get an idea of how much I'm really feeding it.

 

Ok, thank you all very much. Glad to see that it is working similarly to others'.

 

It is working fine.
Look at it as a Broad Brush type of tool.
It's basicly designed to give instantaneous feed back at a glance of how economically or uneconomically you are driving by the general position of the gauge. Despite the appearance of actual numbers on the guage, it's not really designed to be used for anything much more than that, when you're above 40 and closer bouncing closer to the top of the gauge...good job when you are below 30 and closer to the 0 part of the gauge..your burning fuel at a higher rate...for whatever reason...engine load or because you are at a stop or moving slowly. Your other meter, will give you the average fuel economy for that tank...which you can reset after a fill.

But if you were concerned it wasn't working right? No. It's doing exactly what it's designed to do. As said, as you drive gas mileage isn't static...and the gauge is just going to reflect the instantaneous changes of fuel useuage. You don't have to watch it so closely that you are saying to yourself...I'm getting 40mpg, oh no, I'm down to 12, whoo! I'm pegged at 80+.....you'll drive yourself nutty.

 

All these freak's QFT

That little bugger can be your best eco friend.