[shane55]

Morning everyone just wondering have any of you seen or has this before? My range is always out by 100 miles at least and my mpg is in the high 50s usually 53-58mpg! I know this wasn't always the case and I could bet its been since I changed my thermostat a few months back...but don't know how this could have caused it, I've reset the bc but it still remains too high!

Shane

[HighlandPete]

Have you calculated the mpg error... brim to brim?

My OBC used to be within 1% accuracy from new, but for some reason it is now about 10% pessimistic against brim to brim figures. I've no idea why or exactly when it changed, but did have a software upgrade when the ignition lock was sorted, other things were updated and wonder if something changed due to that.

The miles remaining is a rolling calc anyway, so that will be changing according to the mpg at the time. I'd not be surprised if any OBC +/- calculation error will just make 'miles remaining' run with a similar ratio of error as well.

HighlandPete

[parapaul]

As Pete said...

Depending how often or recently you reset your OBC, it will take some time for the mpg to settle down, particularly if your most recent driving has been especially economical.

Range is dependent on (IIRC) your last 30 miles driven. If you've just done a long m/way trip it will be optimistic, but a good thrash or a stop-start town drive will drop it dramatically.

[AlwynMike]

Has anyone tried / had success in adjusting the mpg using the "hidden menu"??

Mike

[shane55]

As the mileage I do is probably a 50/50 mix of town and country driving I know my average mpg used to sit at 37 for ages until i noticed it then went eratically high constantly above 50.

Ive attached a pic of my mpg from an ap I have on my phone, the obc used to be almost spot on accurate until lately...maybe its the fact that I keep resetting it when doing high mpg that its leaning on the high end!

[bmw3series2010]

Originally Posted by shane55

As the mileage I do is probably a 50/50 mix of town and country driving I know my average mpg used to sit at 37 for ages until i noticed it then went eratically high constantly above 50.

Ive attached a pic of my mpg from an ap I have on my phone, the obc used to be almost spot on accurate until lately...maybe its the fact that I keep resetting it when doing high mpg that its leaning on the high end!

what app is this mate

[parapaul]

I leave the OBC untouched, mine's sitting at a steady 35mpg over the 12ish months I've had the car. If I want to know the figures for a specific tankful, I use the Journey Computer function of the iDrive.

[shane55]

Originally Posted by bmw335iconvertible

what app is this mate

It's road trip LE ;-)

[E92westy]

Originally Posted by AlwynMike

Has anyone tried / had success in adjusting the mpg using the "hidden menu"??

Mike

You certainly can calibrate the OBC using the hidden menu.
I have done this several times.
It can be very accurate....

To the OP-
I'm sure a quick search will reveal all.... ;-)

[AlwynMike]

Originally Posted by E92westy

You certainly can calibrate the OBC using the hidden menu.
I have done this several times.
It can be very accurate....

To the OP-
I'm sure a quick search will reveal all.... ;-)

I may well be asking your advice later in the year then!
My OBC seems to be out.
I mentioned it when my car went in for other warranty work, and was told it was "within tolerance". I'd only had a couple of tank fulls through at that stage, so I couldn't say too much. However, since then I have been keeping records and I plan to hit the Dealers (Rybrook Shrewsbury) with some more accurate figures to work to - before the warranty expires!
Being the dyed-in-the-wool cynic, I am expecting the Dealer to fail at this task, and will end up doing it myself.
It would be good to know which way and which figures to alter to get a more correct figure.