[JOHNBMWM5]

Originally Posted by Mikey0423

Interesting not noticed it on my 16LCI will have to check it, I have noticed things that were on older ones are missing.

I have it on my 2016 535D MS.

[Johnny Grabble]

Originally Posted by JOHNBMWM5

Not available to older cars, LCI only.
Go to: settins<driving mode<configure Eco-pro, and iif there is a box to tick, tick it.
But at 2011 I doubt it.

2015 535d. Doesn't have it. Can't say I'm bothered, the fuel consumption is OK.

[danorman777]

My 2016 535d has it.

Going down hill I notice the difference in having it on or off as it doesn't reduce speed as much on a down slope with coasting on.

[MrPogle]

Mine doesn't. You would assume that BMW know what they are doing but coasting sometimes saves fuel and sometimes costs fuel. Anyone know how smart it is in deciding when to coast?

[JOHNBMWM5]

Originally Posted by MrPogle

Mine doesn't. You would assume that BMW know what they are doing but coasting sometimes saves fuel and sometimes costs fuel. Anyone know how smart it is in deciding when to coast?

How can coasting cost fuel, the fuel pump all but off.

[AP]

a guess but if coasting , some fuel required to keep the engine turning over.
If in gear, the gears will keep the engine turning over - no fuel required but their will be some friction so the cars slows down. (engine braking)

good question though.

[MrPogle]

Originally Posted by JOHNBMWM5

How can coasting cost fuel, the fuel pump all but off.

Imagine coming up to some red traffic lights. You get off the accelerator, head towards them and when you get close you apply the brake to come to a standstill.

Without coast. When you come off the accelerator the injectors shut down and you slow down due to engine braking until you apply the brakes. Then you use some brakes to stop. You burn no fuel and use some brake pad.

With coast. When you come off the accelerator you "freewheel" towards the lights. You slow down less due to the lack of engine braking so you have to use more brake pad to stop and the engine has to be kept running on your approach to the lights. So you use more fuel and more brake pad.

[danorman777]

All sounds logical, so why do BMW have it as an option?

[JOHNBMWM5]

Originally Posted by MrPogle

Imagine coming up to some red traffic lights. You get off the accelerator, head towards them and when you get close you apply the brake to come to a standstill.

Without coast. When you come off the accelerator the injectors shut down and you slow down due to engine braking until you apply the brakes. Then you use some brakes to stop. You burn no fuel and use some brake pad.

With coast. When you come off the accelerator you "freewheel" towards the lights. You slow down less due to the lack of engine braking so you have to use more brake pad to stop and the engine has to be kept running on your approach to the lights. So you use more fuel and more brake pad.

If lights change on me I use the gear paddle to drop gears straight away disengaging coasting , no fuel used at all.

[MrPogle]

Originally Posted by danorman777

All sounds logical, so why do BMW have it as an option?

Because there are situations where is does save fuel. Generally it is more efficient to slow-down/speed-up as little as possible and coasting makes this more possible.

If you are on the motorway and you just back-off a bit to avoid crowding the guy in front, it's probably better to not actually use the engine braking so coasting is a fuel saver.

Hence my question about how smart it is. The cars knows if you are on the M6 in medium traffic or if you are approaching a T-junction on a country lane. It could factor that in when it decides if it is worth coasting or not.

A friend of mine has a push-bike that does indicators automatically. Imagine the pandemonium if BMWs suddenly all started to indicate.

[danorman777]

Lol!

I thought it was Audi drivers now.

That all makes sense and I do notice a lower deceleration with it on.

I will experiment.

[HighlandPete]

Originally Posted by MrPogle

Imagine coming up to some red traffic lights. You get off the accelerator, head towards them and when you get close you apply the brake to come to a standstill.

Without coast. When you come off the accelerator the injectors shut down and you slow down due to engine braking until you apply the brakes. Then you use some brakes to stop. You burn no fuel and use some brake pad.

With coast. When you come off the accelerator you "freewheel" towards the lights. You slow down less due to the lack of engine braking so you have to use more brake pad to stop and the engine has to be kept running on your approach to the lights. So you use more fuel and more brake pad.

Good points, something I was thinking when coasting was first added, but never followed up how The BMW coasting feature really works.

Does the engine shut down, like start-stop, at any times coasting is used?

I've assumed free wheeling has proven to be more fuel efficient than the over-run situation where the fuelling is off, above a certain rpm.

The other question, if coasting is in operation that must impinge on the harvesting of energy for battery charging, as it seems in conflict with the boosting of the battery on the over-run.

I suggest it requires some very smart energy management.

[JOHNBMWM5]

Originally Posted by HighlandPete

The other question, if coasting is in operation that must impinge on the harvesting of energy for battery charging, as it seems in conflict with the boosting of the battery on the over-run.

I suggest it requires some very smart energy management.

Harvesting still works when Coasting on mine.

[danorman777]

I don't think mine harvests when it is coasting based on the eco pro display as the needle on the display stays in the middle?

BMW's website says..

Another feature of the ECO PRO Mode is the coasting function in combination with Steptronic transmission: if within a speed range of 50–160 km/h the driver takes their foot off the accelerator and does not brake, the system disconnects the engine and the car coasts – i.e. rolls without engine power.

Not a lot of help!!

[HighlandPete]

Originally Posted by JOHNBMWM5

Harvesting still works when Coasting on mine.

Is it showing the feature on the display during coasting?

If you are at idle rpm, while coasting, then there is no 'regeneration' possible, as you have to adjust the fuelling to drive an alternator, ("nowt for free"), you are not harvesting wasted energy, (there is no waste), like you can on the over-run as part of engine braking.

It is either a speed related change over, or there has to be some smart energy management, if it is going to balance battery charging and coasting. It would have to select which is the most energy efficient/saving (or give priority to the battery if necessary), in every slow down situation.

[HighlandPete]

Originally Posted by danorman777

I don't think mine harvests when it is coasting based on the eco pro display as the needle on the display stays in the middle?

BMW's website says..

Another feature of the ECO PRO Mode is the coasting function in combination with Steptronic transmission: if within a speed range of 50–160 km/h the driver takes their foot off the accelerator and does not brake, the system disconnects the engine and the car coasts – i.e. rolls without engine power.

Not a lot of help!!

May be it is does help.

Does coasting disengage below 50km/h? If so, then below that speed energy harvesting can swing over to the alternator on further over-run.

[danorman777]

Good point. So maybe is ok on when approaching lights as not actually active then.

[JOHNBMWM5]

Originally Posted by HighlandPete

Is it showing the feature on the display during coasting?

If you are at idle rpm, while coasting, then there is no 'regeneration' possible, as you have to adjust the fuelling to drive an alternator, ("nowt for free"), you are not harvesting wasted energy, (there is no waste), like you can on the over-run as part of engine braking.

It is either a speed related change over, or there has to be some smart energy management, if it is going to balance battery charging and coasting. It would have to select which is the most energy efficient/saving (or give priority to the battery if necessary), in every slow down situation.

My car when coasting shows the pointer going into the + side of the dial, therefor charging. no?.
Not every time though, more when going down hills.

[HighlandPete]

Originally Posted by JOHNBMWM5

My car when coasting shows the pointer going into the + side of the dial, therefor charging. no?.
Not every time though, more when going down hills.

From what I read, coasting totally disengages the gearbox. Therefore no energy recuperation to the battery is possible, (engine is on idle) until the road speed is below ~30mph, where coasting is disengaged and the battery charging can take over as the engine/alternator is 'powered' on the over-run by the car's momentum.

Do you see the revs climb at the lower speeds, as coasting disengages?

It may be as simple as coasting being engaged, or not. Intelligent energy management may have a part in whether coasting is disabled, if battery SOC (state of charge) is low and changing requires priority.

[JOHNBMWM5]

Originally Posted by HighlandPete

From what I read, coasting totally disengages the gearbox. Therefore no energy recuperation to the battery is possible, (engine is on idle) until the road speed is below ~30mph, where coasting is disengaged and the battery charging can take over as the engine/alternator is 'powered' on the over-run by the car's momentum.

Do you see the revs climb at the lower speeds, as coasting disengages?

It may be as simple as coasting being engaged, or not. Intelligent energy management may have a part in whether coasting is disabled, if battery SOC (state of charge) is low and changing requires priority.

Can't see revs as such in Eco-crap it's the blue dial, however the pointer does move clockwise which would indicate revs increasing.

[Johnny Grabble]

Originally Posted by JOHNBMWM5

Can't see revs as such in Eco-crap it's the blue dial, however the pointer does move clockwise which would indicate revs increasing.

If you have the multi functional instrument panel you can go into settings and change the Eco Pro display so that it looks just the same as the display in Comfort or Comfort+. Then you'll be able to see what happens too the revs during coasting.

[JOHNBMWM5]

Originally Posted by Johnny Grabble

If you have the multi functional instrument panel you can go into settings and change the Eco Pro display so that it looks just the same as the display in Comfort or Comfort+. Then you'll be able to see what happens too the revs during coasting.

Aghh, did not know that, thanks.
How do I do that out of interest?.