What I wasn't understanding is why I can save 33% in the megane without FCD, while I can save only 20% in the scenic with FCD...
After 3 tanks in the scenic, it seams I'm improving myself, noticeably as the temperature is dropping. Thanks to the onboard computer I can say that when the ICE is cold it consumes 5.2L/100 (10% saving from the 5.9L/100 rating), while when it's hot it consumes only 3.5L/100 (40% saving).
At 70km/h I can find the sweet spot at 2.3L/100, and at 80km/h it's at 3.0L/100. Now these hot spots are so volatiles that any change in road level or a truck overtaking me and the consumption increases by 10-20% and/or the speed decreases by 5-10% !!!
3 possibilities I imagine :
- the heavier weight and greater Cd and FA of the scenic make it more sensible to road conditions.
- as I drive nearer from scenic's sweet spots (as I drive by looking at the FCD), the gas waste is smaller and doesn't permit to absorb the changes in road conditions without generating a speed change.
- the high grade diesel (cetane 55 instead of 51) has less impact in scenic's more complex common rail turbo diesel engine than in megane's simpler turbo diesel engine.
As my wife and I are swapping our cars regularly, from tomorrow I get the megane back
Since I'm eco-driving, I prefer the megane which is lighter, while my wife prefers the scenic which is higher.
Denis.