MPG indicator?

[Tom K.]

Originally Posted by jeremyc74

That makes sense. Can you have different readings displayed on iDrive and the gauge display, or is it connected together?

iDrive gives you a completely independant trip computer showing range (miles to empty), avg. speed, avg. mpg, and estimated arrival time & distance if you've entered a destination. Instantaneous mpg is only shown on the dash display as it would be redundant. IIRC, the miles to empty is the same as the regular OBC but the others are not, unless you reset both at the same time.

When on an extended trip, I find the iDrive computer useful for daily records of mileage, etc. and I use the dash avg. mpg readout for each tankful.

(I knew there was a justification for spending $2,100 on the iDrive/Navi package!!)
Tom

[Schilliard]

Does anyone know exactly how the instantaneous reading is calculated? I assume it's not measured...

[jkp1187]

Originally Posted by jeremyc74

Yeah but you can pull up the same info on the stereo display at the same time. I just can't remeber how it displays everything (one at a time or all together)

I recall seeing it all together when I played around with it on my test-drive. Stereo display, not iDrive.

C'mon guys, I don't even own a 1er yet....

[jeremyc74]

Originally Posted by Schilliard

Does anyone know exactly how the instantaneous reading is calculated? I assume it's not measured...

Fuel injector duty cycle usually. The injectors are really precise, so knowing how long they're open allows a pretty accurate calculation. I find mine to be within .5 MPG of actual measured mileage.

[Tom K.]

Originally Posted by jeremyc74

Fuel injector duty cycle usually. The injectors are really precise, so knowing how long they're open allows a pretty accurate calculation. I find mine to be within .5 MPG of actual measured mileage.

Mine also - a big improvement over the avg. 9% optimistic MPG readout in my '99 E46.

Tom