D- or B-mode driving

General Discussion
21

Hi Jactac, the E-save function is realitively waste of space on a standard journey. But if you are driving say to work and home agin, you could E-save half the capacity for your homeward trip. This means both trips would be in Hybrid mode and the car deciding what power train to use when.

I ask myself when starting off, “before I get home will I need to use petrol (based on current electric range)” , if so I switch to either Hybrid or Comfort mode and let the car do its magic. If I think I will not need petrol I stay in electric only mode and at £0.88p for 20+ miles why not!

I must add that I have the ability to recharge when ever I’m at home.

Also, I’m an anorak, I have recorded every time I have charged and refuelled my car since ownership.
I have travelled 3,600+ miles (775 electric only) , used about 55 litres of petrol and 804kW of electricity. The average mpg over those Hybrid only miles is 79 mpg, using the eMpg conversion it’s around 91.9 eMpg

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22

Well that supprises me, most PSA group cars use the Tom Tom connected Satnav, so the yshould all perform the same. It wasn’t until I chatted to other owners that we realised the destination as way point trick to use the battery over whole trip not just one way.

Yes, my car also uses battery on motorways, my most recent motorway trip, November, 98 miles, 80% motorway (70ish mph) gave me 71 mpg, full battery to start empty when I got home, using the Satnav. Day before 0% battery, motorway 60mph it returned less than 40mpg over 36 miles.

You do use just hybrid mode and not Power/Sport mode?

In fact, so I can put my car away at night on Electric I have told my Satnav that my house is further 50 metres away.

23

I only use Comfort mode and electric. Never Sport or hybrid.
Afaik, hybrid and comfort is the same except for the active scan suspension only works in comfort, that’s why I use comfort.

So do you know exactly what the car’s goal is with knowing the destination?
Is it to evenly distribute battery power along the journey, or is it to concentrate battery power to the slower sections (e.g. built-up areas, suburbs, city driving etc.) of the journey?
I would prefer the latter, because otherwise it’s useless.
The overhead energy waste of the petrol engine is enormous on slow roads and city traffic, while it’s much less on motorway.
I abandoned the built-in satnav after discovering that it wasted battery on motorways anyway, so it’s been a while since I made a proper journey like that. I use google/waze/apple maps via carplay now, and control the battery deployment manually. Much better.

24

I’ve looked but can’t find where I see it, it’s a TOMTOM video on YouTube, the Satnav knows where you are, and what’s coming up ahead.

For instance (using SATNAV & Hybrid/Comfort modes), your comments regarding wasteing electric on motorways… If you watch what is happening, you will probably see that on an incline the car will use petrol and electricity - as that is the most efficient, down hill, and coasting it will shut the engine down and use electric, adding power to the battery through slight regen, on level roads, it will most likely constantly switch between the two, always trying to find the most efficient form of power but slightly weighted towards electricity and always tries to add power to the battery with regen. Sometimes the engine will not stop, just idle for a while.

It also knows that at certain times on you journey you will be driving slower and save some power for that.

For example, The navigation system knows that the last 2 mile before getting to my house it can drive in EV only mode so it does, 30mph.

25

I understand the efficiency point with using battery power in e.g. inclines on the motorway, but the gain is still a lot less compared to using it in urban areas for example, and when I have 500km to drive and the battery is empty before I reach 50km, you gotta wonder about the competence of the system.
Anyway, if/when I get a decent chance to test it again, I will.

26

Obviously that is without the inbuilt navigation, helping, I even use the navigation on ‘simple’ trips. The car will always use electric first, unless it can see into the future.

With current temperatures, you’re getting what, 30 km to a charge? So program the navigation for a 40-50km round trip and see what happens.

27

Not according to my recollection.
Like I said, the reason I stopped using it was because I didn’t see the behavior from the system that you’re talking about.
But I will try it out again.

28

Slightly off subject.
Today I had a loan DS4 off the dealership same spec as mine except it was a diesel.
I’ve run around all day in it and I was very impressed with the fuel economy and the performance, however I found the engine noisy.
It had a proper diesel knocky engine, not something I could put up for long if I’m honest.

It might just be that my E Tense is so quiet, even with the engine running, and I’ve been spoilt.

29

B mode saves wear and tear and money.
Regen is “free” well reclaimed energy which would otherwise be wasted as heat from your friction brakes.
It uses the motor as a generator causing the braking effect.
The challenge is getting used to driving with one pedal, it is possible to “balance” the accelerator pedal so you are neither drawing power or regen braking, you might get cramp :smile:
Our E-Tense I have never seen more than 32 miles on the electric meter. Driving with scant passenger consideration and lots of anticipation I have managed 37 miles. Keeping up with the traffic, without touching the brakes, coasting as much as possible and trying not to regen at all.
Regen is only about 30% efficient but that is 30% more than friction braking.

30

Incorrect.
Brake pedal regens just as much as B-mode.
Only if you brake really hard (“panic braking”) you use “friction braking”.

31

Doesn’t it all depend on how much charge is already in the battery ?

I’ve seen the regen gauge go all the way to max without touching the brakes, just coasting to a stop, and I’ve also seen the gauge barely move when coasting and using the brake pedal at the same time.

I feel it varies on how much charge the battery is already holding.
I might be wrong but I dont think I’ve seen the brake pedal breaking regens as much as B mode ?
But I might be wrong ?

32

Of course it can depend on charging level. If your battery is full, there’s nowhere to put the energy, I would assume.
My point here is simply that B-mode and brake pedal both uses the same engine braking technique.
Since I rarely use E-save Max to charge the battery to full, I also rarely ever see braking having no regen effect. My manual braking always initiates the charging gauge to move to green. Exactly the same that happens if I use B-mode.

33

It blends the braking, well before panic braking you are using the friction brakes.

34

Here’s what in my operation manual (app based) under regenerative braking. And eco driving.

20241219_141819
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So what does this mean when it states has no effect on charge level indicator ?
It must have some effect because you can see the indicator altering as its regenerating ?

Also the rear brake lights do come on.
I believe its law now here in the UK.

36

Cheers!
Says nothing about brake pedal having less effect than B-mode. Makes perfect sense.
Also says to first “anticipate slowing down”, which is exactly my “lift & coast” theory.
However, after that they apparently think that you should try and use B-mode if possible, but it doesn’t explain why you can’t might as well do that with brake pedal. Also, it’s rather cumbersome to first coast in D and then having to use the gear lever to switch to B.
I really hate when instructions are contradictory, or simply leave things out like that.
Anyway, I feel like I have enough info to continue my D-mode driving with lift & coast. :sunglasses:

37

The manual is very misleading, not just regarding the regen braking.

When I was trying to sort out the keyless entry & welcome lights, it doesn’t give enough detail, it tends to only half explain how a feature should function, which sort of misleads you into thinking something isn’t working as it should but the problem is the explanation in the manual.

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38

Screenshot 2024-12-19 at 14.50.47

What do they mean by this ?

39

Your guess is as good as mine.
It’s definitely visible on what I would call a charge level indicator (the one with “power | eco | charge”).
And it’s visible on the car visualization where power goes in and out of the battery and to and from the wheels.
Could they mean the actual battery distance estimation number? (Like “28 km”)

40

So what does this mean when it states has no effect on charge level indicator ?

They mean the level of charge in the battery x%

It must have some effect because you can see the indicator altering as its regenerating ?

Yes the regen indicator moves and range increases but the percentage of charge doesn’t

Also the rear brake lights do come on.
I believe its law now here in the UK.

No they don’t and I think you’ll find the UK law, or more the EU regulations state a certain level of inertia is required to become a legal requirement for brake light illumination. If it were then why not while changing down a few gears in a petrol car do the brake light not come on? - Oh, by the way when using drive assist/Cruise control the do automatically.

Says nothing about brake pedal having less effect than B-mode. Makes perfect sense.

I don’t think it does, its just you are already slowing down quickly anyway.

Anyway, I feel like I have enough info to continue my D-mode driving with lift & coast.

Exactly like I do, lift and coast, use the brake pedal to keep the regen at its maximum, but I am aware the brakes have to be used to keep calipers working and discs clean, so the last couple of meters of pure braking helps this.

Screenshot 2024-12-19 at 14.50.47

What do they mean by this ?

I was in Scotland earlier this year, long slow hill, regen’d all the way down, some in “B” mode, estimated range went up but the percentage of charge didn’t - work that one out?

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