[E91-Norway]

Hi!

On my F30 2012 I pictured this numbers after one hour drive..strange

[Sladester100]

What's your question?
Highlighted is the average consumption for that journey - 5.5litres per kilometre

[E91-Norway]

Originally Posted by Sladester100

What's your question?
Highlighted is the average consumption for that journey - 5.5litres per kilometre

Check the journey part of the screen;
1 hour drive
Distance and average km per hour are not equal. Is that correct?

[KellerKiller]

I don't think those fields on your left screen reset automatically, even when you input a new destination in the navi. Try it again, but make sure before you leave that you manually zero out all stats in the computer.

[TonyS]

I don't think that's what the OP is saying. If you look at the right hand screen (journey computer) it shows that he's travelled 97km in exactly 1 hour but his average speed was 99.3km/hr rather than 97km/hr.

[Vitoco]

well, maybe almost a whole minute has passed and its about to show 1:01, during which time he has managed to drive a bit (or a lot) faster letting the average speed increase a bit. Perfectly plausible

[MikeVictor]

Main display is showing the standard OBC readouts that you can also see on the dash, and the split is showing the JC which was reset at the start of the journey.

Difference is the OBC showing average consumption over a different period as it likely wasn't reset when the journey commenced.

[E91-Norway]

Originally Posted by TonyS

I don't think that's what the OP is saying. If you look at the right hand screen (journey computer) it shows that he's travelled 97km in exactly 1 hour but his average speed was 99.3km/hr rather than 97km/hr.

Exactly!

[E91-Norway]

Originally Posted by Dabaitu

Main display is showing the standard OBC readouts that you can also see on the dash, and the split is showing the JC which was reset at the start of the journey.

Difference is the OBC showing average consumption over a different period as it likely wasn't reset when the journey commenced.

Som basic information:
Its all about the Journey Computer on the right side of the screen.
The setting says that the JC shall automatic reset if the car has been parked more than four hours. So when I started driving this morning the JC was reset, all values was 0.
I pictured the screen approx 3-5 second after the driving time past 1 hour. I was prepared with my iPhone camera because I noticed that the values had unnormal difference after driving 58 minutes.

Interesting or not?

[MikeVictor]

Originally Posted by E91-Norway

Som basic information:
Its all about the Journey Computer on the right side of the screen.
The setting says that the JC shall automatic reset if the car has been parked more than four hours. So when I started driving this morning the JC was reset, all values was 0.
I pictured the screen approx 3-5 second after the driving time past 1 hour. I was prepared with my iPhone camera because I noticed that the values had unnormal difference after driving 58 minutes.

Interesting or not?

Not. The time period for the OBC measurement is different to the JC measurement, hence the difference.

The Owners Manual isn't overly detailed on this point:

Average fuel consumption
This is calculated for the period during which the
engine is running.
The average fuel consumption is calculated on
the basis of various distances.

So what's giving the discrepancy is likely the OBC and JC measuring different time periods, giving you the different result. Does this make sense or have I completely missed your point?

[E91-Norway]

Originally Posted by Dabaitu

Not. The time period for the OBC measurement is different to the JC measurement, hence the difference.

The Owners Manual isn't overly detailed on this point:

Average fuel consumption
This is calculated for the period during which the
engine is running.
The average fuel consumption is calculated on
the basis of various distances.

So what's giving the discrepancy is likely the OBC and JC measuring different time periods, giving you the different result. Does this make sense or have I completely missed your point?

It's all about the JC and the drivven distance and the average speed per hour. In my mind the drivven distanse and average km/per hour should be equal when I have been driving for exactly 1 hour after reseting of the JC.

[Peef]

I'm guessing the root of the problem is that the BMW speedometer reads artificially high, per German law. If the trip computer is averaging the signal from the speedometer, it, too will be artificially high.

The odometer, on the other hand, is likely quite accurate, for other (mostly legal) reasons. That probably explains the discrepancy.

[MikeVictor]

Originally Posted by E91-Norway

It's all about the JC and the drivven distance and the average speed per hour. In my mind the drivven distanse and average km/per hour should be equal when I have been driving for exactly 1 hour after reseting of the JC.

Ah I get it now, sorry for my confusion.

Did you reset your JC when you were already travelling 100km/h? Or did you take it from a standing start?

[E91-Norway]

Originally Posted by Dabaitu

Ah I get it now, sorry for my confusion.

Did you reset your JC when you were already travelling 100km/h? Or did you take it from a standing start?

From a standing start.....as normal is..

[TonyS]

Originally Posted by Peef

I'm guessing the root of the problem is that the BMW speedometer reads artificially high, per German law. If the trip computer is averaging the signal from the speedometer, it, too will be artificially high.

The odometer, on the other hand, is likely quite accurate, for other (mostly legal) reasons. That probably explains the discrepancy.

Now that sounds quite feasible.

[E91-Norway]

Originally Posted by TonyS

Now that sounds quite feasible.

OK, It's a known issue that the speedo shows a little more than reality.
But I can't find it reasonable that the AVG Speed in the Journey Computer should put out wrong values.

AVG, as we learnd in school is: Distance ÷ Time.

Why should BMW use any hidden values to calculate the average speed?
If so, it would have been interesting to know how and why they make this missmatch from normal calculations.

Because in my JC the values are not correct.

[Peef]

Originally Posted by E91-Norway

OK, It's a known issue that the speedo shows a little more than reality.
But I can't find it reasonable that the AVG Speed in the Journey Computer should put out wrong values.

AVG, as we learnd in school is: Distance ÷ Time.

Why should BMW use any hidden values to calculate the average speed?
If so, it would have been interesting to know how and why they make this missmatch from normal calculations.

Because in my JC the values are not correct.

Right - but keep in mind each of those values in the trip computer can be reset independently. If you reset the odometer value, the average speed will not budge. Therefore, the average speed calc must be getting it's data from the speedo and integrating it.

[E91-Norway]

Originally Posted by Peef

Right - but keep in mind each of those values in the trip computer can be reset independently. If you reset the odometer value, the average speed will not budge. Therefore, the average speed calc must be getting it's data from the speedo and integrating it.

...but in the Journey part all values are reset automatic when four hour station. Beside, in the journey comp there are no opportunities to reset parts of the values. This because it should give you "correct" information about your active journey....So there have to be another explanation