Quote:
Originally Posted by MetroMPG
Welcome to the forum, Michaelflat1!
What size engine is in your Jazz?
How did you determine the fuel cut-off point (RPM) - does the car's gauge show instant fuel consumption?
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1.3 (marketed as 1.4) i-dsi engine. The fuelcut points i can feel sometimes (I think my car has a sticky EGR valve/throttle body/somethings wrong, it can be jerky/very noticeable coming out of fuelcut)
Also i monitor fuel flow using OBD2 bluetooth adapter, and TorquePro. (only have avg MPG on the car's trip computer)
My jazz, has electronic throttlebody too, and you can see it slowly closing the throttle as you slow down (presumably to increase engine braking at low speeds, giving it a nice coastdown)
14% is around idle throttle and in DFCO it'll go from 20% to 15% throttle as engine RPM decreases (20% from around 3500rpm, 15% at around 1300rpm). Dependant on driving style too, if you mash the gas a lot, the gas pedal becomes more responsive, and the throttlebody doesn't open as much when off gas (to reduce rev hang). Consistent gentle driving is very beneficial in this car.
I find the close ratios useful, to keep engine rpms low. I love driving manual however, and find it quite fun to change gear a lot (i change gear sooo much, town driving is variable speed and i try to use DFCO as much as i can, smoothly).
I can see holding 2nd gear not being a disaster in regards to fuel economy, but only if you use close to WOT, keep that engine loaded, don't leave it crying out for a gear change come 40kmh.