ECO Mode - Right Hand Dial

[Haldex]

I think both of you (Quacker and mdm) are right- on steep descents engine braking is required for safety reasons + consumption is lower if in gear with no throttle- whereas on flat (or near-flat..) sections (where engine braking is not required..) consumption benefits from freewheel rolling - as the car maintains the speed for some time- due to inertia.. And this is exactly how Volvo designed the freewheel coast function:

"Free-wheel function Eco Coast
The freewheel function Eco Coast means in practice that engine braking ceases, meaning in turn that the car's kinetic energy is used to freewheel for longer distances. When the driver releases the accelerator pedal the gearbox is automatically disengaged from the engine whose speed is reduced to idling speed with reduced consumption. The function is best used where it is possible to freewheel a long way, e.g. roads with a slight downhill gradient or when there is a predictable speed reduction to freewheel into a zone with a lower speed limit.
Activating the freewheel function
The function is activated when the accelerator pedal is fully released, in combination with the following parameters:
Drive mode Eco is activated.
The gear selector is in D position.
Speed within the range of approx. 65-140 km/h(40-87 mph).
The road's downhill gradient is not steeper than approx. 6%.
The driver display shows COASTING when the freewheel function is being used.
Limitations
The freewheel function is not available if:
Engine and/or gearbox are not at normal operating temperature.
The gear selector is moved from the D position and the manual position.
The speed is outside the range of approx. 65-140 km/h(40-87 mph).
The road's downhill gradient is steeper than approx. 6%.
Manual gear changing is performed with the steering wheel paddles*."

[Quacker]

Originally Posted by Quacker

Don’t worry about coasting. It actually uses more fuel than if a gear was engaged, because on engine over-run all fuel is cut off, compared to coasting where enough fuel must be consumed to keep the engine idling. While this may not be much, consider that it is significant enough to bother fitting cars with idle engine stop/start hardware. Another bit of rubbish, cars could do without.

No, I'm not that Australian and I didn't put him up to making this video. However, like me, he is an engineer.

[YOUTUBE]https://youtu.be/GOc-0l3lfrY[/YOUTUBE]