MG4 Adaptive Cruise seems very nervous?

[mg4mc]

Far too aggressive slowing down and accelerating. Go over a small hill brow and it goes over the limit, slams on the regen and undershoots the limit by several mph, then accelerates hard to catch up. The worst ACC I have experienced by a long long way.

We did a fairly flat 100 mile journey the other day, me in control on the way there and got 4.3 ml/kWh, used ACC the bulk of the way back with a slightly slower motorway speed set and the return got 3.9 ml/kWh. (No A/C either way).

 

[Big Ears]

I just posted about the MG3 Trophys ACC and it too is useful but a bit rubbish in its operation.

 

[DixieTGS]

We did a fairly flat 100 mile journey the other day, me in control on the way there and got 4.3 ml/kWh, used ACC the bulk of the way back with a slightly slower motorway speed set and the return got 3.9 ml/kWh.

You also need to rule out the wind contributing to the difference. Even in our ICE with a moderate wind I've had 46 MPG going West to East, then 38 going East to West 2 hours later.

 

[NLMGSAN]

Far too aggressive slowing down and accelerating. Go over a small hill brow and it goes over the limit, slams on the regen and undershoots the limit by several mph, then accelerates hard to catch up. The worst ACC I have experienced by a long long way.

We did a fairly flat 100 mile journey the other day, me in control on the way there and got 4.3 ml/kWh, used ACC the bulk of the way back with a slightly slower motorway speed set and the return got 3.9 ml/kWh. (No A/C either way).

Wind?
Edit: matter was already brought up.

 

[marty21]

So, almost 2 weeks in...

I've found using ACC to be really quite nice. Yes, it can decelerate quickly, and it doesn't pick up as quickly as I'd like, but around town, it seems to be a nice ride.

Driving along the A14, things get a little different. If someone pulls in front of me, it'll slow very quickly, but I've found that if I want to overtake, I override the system with my right boot, and then once up to speed, off the pedal and carry on.

Maybe over the coming months, it'll annoy me more, but at the mo, I'm pretty happy with it.

Just my thoughts, and I don't want to take away from anyone else's experience.

Check your regen level….on level 1 it’s quite forgiving on deceleration when traffic moves into your lane….

 

[marty21]

The reason for using ACC is to not bother using my right boot.
It only happens if you go too close to the car in front of you. Then it drops the speed,even you are in the next lane and the displays shiws the other vehicle is in an other lane. I have a video clip showing my car still drops speed from from 99 to 89 kmh. Completely useless (accelerating again cost you more than was regenerated), and dangerous for those approaching you.

You can modify this response by being in regen level 1 and also the inter vehicle distance setting (left toggle switch on steering wheel….set it to min)…

 

[decrep]

I've tried level 1 regen and different distance levels, and it's still something I can't live with. I'd rather catch the bus than drive a car like that.
No matter what you do it's still driving on the car in front. For good anticipatory driving you need to be looking at about 5 cars ahead.

 

[decrep]

and woops again, how do you delete multiple posts?
Something confused me, it looked like the posts weren't going, so I kept trying.

 

[Coulomb]

how do you delete multiple posts?

To delete a post, simply edit it to a single dot or something like "please delete". Some kind moderator will find it and delete it for you.

This forum doesn't allow ordinary users to delete their own posts.

 

[decrep]

To delete a post, simply edit it to a single dot or something like "please delete". Some kind moderator will find it and delete it for you.

This forum doesn't allow ordinary users to delete their own posts.

Thanks kind moderator, sorry to make you work

 

[NLMGSAN]

I've tried level 1 regen and different distance levels, and it's still something I can't live with. I'd rather catch the bus than drive a car like that.
No matter what you do it's still driving on the car in front. For good anticipatory driving you need to be looking at about 5 cars ahead.

That is my experience as well. It just reduces the regen and lengthens the coasting. As the text book says.
But the moment that ACC starts reacting to a slower car ahead of you does not change. Neither does it accelarate more timely when overtaking.
Adaptive mode is supposed to help a bit (reduces regen), but only after the car detects that you are within the set distance to the car in front of you (which according to Jerry Pan is based on the 2, 3 and 4 second distance rule). This focus on the car in front is one of the reasons that mg4 drivers say it does not look 2,3 cars ahead for smooth and anticipated driving. Which is very correct...
Another reason that ACC bugs me is related to common situation on highways when there is a lot of traffic, but not enough for a traffic jam. We all have learned that after overtaking you should go back to the right (UK left) lane. The minimum distance with me driving 100kmh is 55 mtrs. And that is a lot. If you cannot directly move over to another lane to overtake the car ahead of you (lots of traffic) you will drive into that 55 mtrs zone and the car starts to brake, trying to level your speed to the car in front of you (asap). Most of times this coincides with the moment you can overtake. So you lose speed and you need your right foot to up it again (ACC override). Because signalling an overtake manouvre does not influence ACC. This repeated braking- accelerating completely denies the purpose of ACC.
ACC for me only works at slower speeds in traffic jams, or at higher speeds on quiet highways (OPD disabled).

 

[mg4mc]

You also need to rule out the wind contributing to the difference. Even in our ICE with a moderate wind I've had 46 MPG going West to East, then 38 going East to West 2 hours later.

I've done the same journey many times, when it's windy I see a big difference too. The journey above was on a windless day; the turbines were all looking very sad and droopy. The temperatures both ways were very similar too.

 

[Mike80]

I'm assuming with ACC on, when it brakes the rear brake lights come on. Hope that's right, any body confirm?

 

[Seajays]

I'm assuming with ACC on, when it brakes the rear brake lights come on. Hope that's right, any body confirm?

Yes, any deceleration above a certain threshold (whether just regen or applying brakes) automatically lights the brake lights.

 

[Big Ears]

Not sure I like that at all.

What I mean is:-

Suppose you're on the M25 doing 70 and the cars in front start to slow down, no brake lights as they just took their foot of the gas, you back off and the brake lights come on so you are now starting a wave of brake light behind you, I've been caught up in this scenario too many times.

 

[siteguru]

It all depends on the retardation rate. By law (i.e. regulations) if the rate exceeds a certain value (1.3 m/s2?) then the brake lights must come on. In the MG4 (where this thread is located) setting a regen level of 1 shouldn't make the lights come on, as the max. regen level is about 5% and similar to ICE engine braking, and (anecdotally) the regen needs to exceed 7% for the brake lights to activate.

 

[Big Ears]

I'm going to have to take a rest Mr Guru all this climbing is wearing me out mate

 

[siteguru]

Climbing what? Mountains of thought?

 

[Big Ears]

Learning.