Quote:
Originally Posted by Piwoslaw
[*]Which braking method uses less fuel?
a) Accelerating until the last moment, then sudden hard braking.
b) Coasting in neutral, then lightly braking.
c) Engine braking (gear reduction if necessary).
Answer: c) Engine braking. Engines with fuel injection cut off fuel when engine braking, allowing the car to travel a certain distance "for free". Coasting in neutral still requires fuel to keep the engine idling.
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Well, I disagree
Coasting gets you a lot further than using DFCO.
The difference in distance travelled would be covered at constant-speed fuel consumption, which will be a lot higher than the idle FC during coasting.
Both techniques may require a dab on the brakes anyway to come to a full stop - but that's when coasting with the engine on is getting less efficient.
I was using DFCO quite a lot before joining EM, only twice doing better than 5L/100km (47mpg).
Coasting engine-on has had a significant impact on my FE since : I think it's the main reason I can regularly get my FC below 5L/100km (or above 47mpg) now.
I had driven @ 100 kph before, without much effect on FE.
Actually, I still see little difference between 100 and 105 kph in FC as the engine seems to be running in a less efficient rpm / load situation at 100kph.
I gain from not accelerating the extra 5kph though.