Remaining range acting weird

[XY2B]

Today I took my MY on a long trip. The efficiency was so bad, I ended up constantly monitoring my remaining milage. I noticed that the number of remaining miles stays the same for a long while (for 2,3 or miles) and then it either skips a number or two or it goes down fast ( a mile every few yards). It did this constantly as if the computer was freezing or lagging. Anyone experienced this.
The car has 400 miles on it. I was driving 70-80 mph most of the way.
ALSO, while on adaptive CC twice the car applied the brakes abruptly with no apparant reason really scary.
Any comments?

 

[MY-Y]

Set your display to energy (battery percent) and use your energy screen set to trip; you'll enjoy your car much more and can leave range anxiety behind.

 

[XY2B]

Thanks.
Its just that we have a 2019 MX and its way better in efficiency and in managing range than the MY. I am just wondering if there is something wrong with the software or battery management system. I have a service appt booked or another reason, I will mntion this one to them as well. will report back if there is something to report.

 

[rfalias]

What was your Wh/MI (or KM) on that trip?

 

[XY2B]

154 WH/km
Which is not accurate at all.

 

[frankvb]

154 WH/km
Which is not accurate at all.

That's around 246 Wh/mile, which IMHO is very good. Why is it not accurate?

 

[XY2B]

Because on other days with slower speed and higher temps. I only managed around 170 wh/ km.
This time around I drove faster and it was windy at least in one direction..

 

[XY2B]

Did another test today, I am basically using 30 - 35% more battery Kms than actual Kms. i.e I need 135 range Kms to travel 100 actual Kms.
Compared to my MX, this is high.