What uses less fuel? Coasting vs Engine Braking

15 Oct 2017

Comments

I have always engine braked in my Focus, while only rarely using the brakes. Good to know that it’s a fuel efficient alternative as well.

You just spoilt the video.
Fun fact: My father has a 1988 Panda, almost never brakes, he knows the roads so good, he could drive blindfolded on them. He knows exactly when to get off the throttle, and then he only brakes a litlle, or doesnt even need to brake

Without watching the video, shouldn’t this be rather obvious? In cars with fuel injection the engine braking uses zero fuel, but when coasting you have to use fuel to keep the engine running.

But not a lot of people find that obvious. I’ve seen enough people, mainly the older generation, who puts the car in N because their minds are still in Carburettor era.

so, when you are engine breaking you are not using fuel to keep the engine running? you switch your car off? you make no sense

Not to mention, the injectors don’t always actually shut off. If you are low in the rev range you may go into idle control. And particularly in automatics they ramp back in on the injectors as you slow down to smooth out your deccel which can use more fuel than N coasting. All of this is highly vehicle dependent of course.

Well my car accelerates if I engine brake downhill, so there’s only normal braking in neutral for me. It only brakes in 1st gear, which is way too slow, in 2nd it just accelerates down no matter what.

Or you could brake with your gear engaged. Your car wouldn’t accelerate AND you save on fuel

I usually engine brake with my vehicles, regardless of if its a manual or automatic. Plus, putting the trans in neutral doesn’t allow the oil pump on the trans to flow as much oil/fluid for your speed.

Mercedes-Benz Trucks have a mode where they automaticly put the gearbox in neutral. It‘s called ecoroll and mercedes says it can safe up to 3% of diesel.

Isnt this for situations where you dont want to slow down and dont accerlerate?

Is gently touching the throttle until the vehicle is effectively coasting while in gear (matching the engine speed to the crank speed to ‘take out the slack’ and eliminate engine braking) the same as putting it in neutral?
i.e. a safer way of putting it in neutral and coasting. Potentially near the bottom of a large hill to gain some momentum into a big up hill.

It is not. In this case, your engine is using the fuel to rev the engine up to a higher speed than in idle, therefore using more fuel. Difference should not be that much, though, unless we’re talking about a really hilly road.. If you don’t feel comfortable putting it in neutral, it is totally fine to feather the throttle while going downhill.

I ussually put it in a higher gear when I want to coast. It seems to work wonders on my fuel consumption.

coasting costs fuel to keep the engine running, engine breaking means your engine keeps running and your revs go up to match your speed, if you think your car maintains higher revs than neutral gear without fuel then i guess humanity has no hope…