[Rich9600]

Short story, my Eco Pro milage gain reset itself after an emergency stop. The tank was about 3/4 full on the gauge, 200 miles done since last fuel up and automatic Eco Pro milage reset.

I was had been caught in roadworks crawling traffic so flicked it into Eco Pro to kill the throttle response to ease keeping a gap and save a little fuel for fun later... I was up to about 0.4 miles saved...

Once through the roadworks the traffic was still slow but flowing. About 40-50mph in very wet and foul weather. So, I'd left a decent gap and was just trundling home. A car decided they could fit in this gap... They couldn't... They just pulled out and didn't accelerate or go anywhere...

So, I basically performed an emergency stop... Winter tyres really grip well in the wet, even at about 9C. A bit of abs thud but great stopping power for the conditions.

After a good hooting and non verbal communication I continued on. Now, the Eco Pro gauge was showing Zero miles... I can only guess the braking force was enough to reset whatever switch is in the fuel tank...

Has anybody else seen similar?

[F30Andy]

I've had it where I've gained ten it so miles in wristcutter mode through a set of SPECS cameras.
Specs has ended, so flicked into sport for a while. When I went back into eco slow the ten miles had turned into 2.

[SkyJawa]

Ignore Eco poo mileage saved gauge as its crap and inaccurate and move on with life

[F30Andy]

Originally Posted by SkyJawa

Ignore Eco poo mileage saved gauge as its crap and inaccurate and move on with life

It's true it is.

No matter how many miles I gain, I still get the same miles out of a tank.

Also I've done entire tanks in eco and in comfort on the same routes and the mileage you get out of the tanks are pretty much the same.

Eco pro and ASS are BMW's most successful sales gimmicks to date.

[teaston]

It was probably time for it to update the mileage anyway, so just a coincidence that it happened at the same time as your emergency stop.

If anything an emergency stop should add to fuel savings due to the brake energy regeneration technology!

[Rich9600]

Originally Posted by teaston

It was probably time for it to update the mileage anyway, so just a coincidence that it happened at the same time as your emergency stop.

If anything an emergency stop should add to fuel savings due to the brake energy regeneration technology!

I thought that the violence of the stop may have activated the reset switch. Possibly something as simple as a float at the top of the fuel tank?

However, I would assume fuel tanks are baffled to prevent excessive slosh?

[SkyJawa]

I'd doubt massively there's anything mechanical to do with the Eco poo gauge, it will all be electronic calcs.......

[Consett Mag]

I had a reading of a few miles gained mid tank, next day I drove in comfort mode for a few miles, then to try using eco pro again, and it started at zero miles.

My impression after a month, is that the eco pro feature is a gimmick on the whole. Infact there's a way to tune the eco pro, but what it does, who knows?!

[HighlandPete]

Originally Posted by Consett Mag

My impression after a month, is that the eco pro feature is a gimmick on the whole. Infact there's a way to tune the eco pro, but what it does, who knows?!

The idea of Eco-Pro is to encourage economical driving, BMW's own words in their blurb. If you try and drive the same as in Comfort mode, then how can you really save fuel? If you go along with the 'elastic band' throttle response then you will save fuel. The modified Climate Control parameters won't really show up this time of the year, on a hot summer day there will be the greatest gain.

Plus something like Climate Control will show more on the smaller engine cars, than on something like the 330d or 335d, where the change in road load is not going to have the same impact.

Get in something like the 320d Efficient Dynamics model and try it there, it does show some pretty impressive gains.

Remember how we drive can swing our mpg by up to something like 35%, with or without Eco-Pro.

HighlandPete

[Rich9600]

Originally Posted by Consett Mag

I had a reading of a few miles gained mid tank, next day I drove in comfort mode for a few miles, then to try using eco pro again, and it started at zero miles.

My impression after a month, is that the eco pro feature is a gimmick on the whole. Infact there's a way to tune the eco pro, but what it does, who knows?!

Yep, you can build up some range in Eco mode, but switch modes and use throttle and it's gone...

I only ever use it in heavy traffic to calm the car and help me to just trundle along...

This sharp stop just seemed to reset it, like fuelling up.

[d4springer]

Maybe slamming on lost your extra points/miles? Looking at the ECO Pro app it wants you to anticipate braking (ie looking at the road conditions ahead and braking gently) so as not to waste fuel accelerating again. Also your not going to gain anything from brake energy regeneration as this wouldn't have time to engauge the alternator as it was effectively a sudden stop.

Some people really are stupid at this time of year though, I find myself constantly defensive driving at the moment.

[HighlandPete]

Originally Posted by Rich9600

This sharp stop just seemed to reset it, like fuelling up.

Not come across the parameters (besides filling up) on which it adjusts the figures. Would have thought it was against a pre-set threshold for your average, then adjust up and down on how driving compares to that threshold.

Whether there was a tank surge which triggered a fill condition, is of course a possibility. I imagine it would require an 'impressive' emergency stop.

HighlandPete

[JD6]

I haven't seen it reset, but there is clearly something wrong with the Eco Pro miles calculator. For example, if I use Eco Pro for 50 miles on the motorway and build up to +3 miles, and then switch into Comfort and drive a bit quicker, the + 3 miles starts to drop.

That makes no sense to me. Surely I have banked those gains irrespective of future driving style?

I gave up on Eco Pro completely after a few early experiments. I don't like the dull throttle response and it seems to make little difference to economy in a 335d, probably for the reasons that HighlandPete has suggested.

[Rich9600]

I only ever use Eco Pro when 'trundling' along in heavy traffic. I don't think the settings specifically save any fuel. However, the 'long' accelerator pedal helps to stop me over accelerating, closing the gap and then having to brake.

I suppose the big stop could have been deemed as wasteful enough to loose my merge points.

Thinking on, fuel tanks must be designed to minimise the slosh with baffles and the like. A full vessel acts like a solid, in terms of its Centre of Gravity. The CoG of a part full vessel is above the liquids surface and related to the 'centre of slosh'. So, a simple fuel tank when part full would raise the centre of gravity of the car. Baffles or a honeycomb structure within the tank would act like multiple solids, so a constant CoG.

So, I think a slosh reset would have been engineered out. However, a mechanical float switch could still have been reset by the forces involved.

I doubt the mechanics can easily be established without excessive parts research or scientific emergency stops...

[pdk42]

Originally Posted by Rich9600

So, I think a slosh reset would have been engineered out. However, a mechanical float switch could still have been reset by the forces involved.

I doubt the mechanics can easily be established without excessive parts research or scientific emergency stops...

I'd be very surprised if the Eco Pro "savings" do any more than consider fuel flow and a bunch of speed/throttle considerations. I doubt fuel level from the level gauge are taken into account at all.

[NISFAN]

The funniest thing about BMW is the ECOPRO route option on the Satnav. It automatically suggests like -8% fuel, even if it is exactly the same route. Remarkable how pressing a button does that for you.