I discovered that my new, manual tranny, EX fit doesn't have an economy mode button or function. It does have two lights, green or blue that show up on either side of the speedometer to indicate relative economy. Does anyone know what those indicator lights are measuring? Are they based on engine vacuum? I also have a Scan Gauge plugged in that gives out mpg.

Because I live in a mountainous, rural area, I often coast in my cars to increase fuel usage by up to 20%. (previous /08 manual Fit). In the new Fit, when I coast, rpm drops to 900, the econ lights shine blue, which is supposed to indicate less efficient use. On the other hand, if, I leave it in gear, but back off the gas, the rpm stays up around 2000-2500 as I go down grades or up to stop signs, and yet the econ lights show green, supposedly using less gas. Anyone know what I'm missing in my assessment here?

 

Injectors shut off when it's engine braking, because the trans in gear will keep the motor spinning. If you're coasting the injectors need to fire to keep the motor idling.

Some people will say that the injectors don't shut off completely when engine braking, but I guarantee they are not using as much fuel as they are when you are idling.

 

What wanderer said—coasting in gear will use less gas than coasting out of gear on any modern car, as the ECU can and will turn off all fuel to the engine while if you're in gear. Of course, that also means that the car slows down more due to the engine braking, but that's not a bad thing if you'd otherwise be using the brakes to slow down (such as when coming up to a light or descending a hill).

I'm assuming it was a typo when you wrote that you coast to increase fuel usage.

 

Drew E and Wanderer, thanks for the clear explanation on the injectors. Yeah, typo. Know anything about those lights on the sides of speedometer? What are they measuring?