[R2Dad]

This bugs me, as I had a 2014 VW TDI wagon that displayed MPG based on actual fuel consumption and not vacuum. But the BMW version shown on my 2017 328d appears to operate the same as cars from the 70's, using vacuum as an analog for mileage. So when the car is idling it says I'm getting over 50 mpg.

Is it like this for all BMWs?

Are there any aftermarket fixes for this?

[Desertnate]

It used to be based on a vacuum long ago. I think my old E46 still operated that way.

These days it is probably electronic/digital, but designed to operate like the old ones. The digital version of your gage on the extended display in my car behaves the same way. It isn't very accurate and is more of a tradition than anything else.

[Billfitz]

When the car is stopped the gauge is off. Logically one might think the reading would go to zero, but for whatever reason BMW has it go fully in the other direction.

[HighlandPete]

Originally Posted by R2Dad

This bugs me, as I had a 2014 VW TDI wagon that displayed MPG based on actual fuel consumption and not vacuum. But the BMW version shown on my 2017 328d appears to operate the same as cars from the 70's, using vacuum as an analog for mileage. So when the car is idling it says I'm getting over 50 mpg.

Is it like this for all BMWs?

Are there any aftermarket fixes for this?

Where's the vacuum coming from, (to measure) in a boosted engine, diesel or petrol? We are not running vacuum manifolds like of old.

What do you mean by any aftermarket fixes for this?

[paul e]

Isn’t the mileage also displayed on the info center in the middle bottom of the screen? (That’s the part that says BMW in the pic.)

That’s where you can also get mpg, etc.

[Desertnate]

Originally Posted by paul e

Isn’t the mileage also displayed on the info center in the middle bottom of the screen? (That’s the part that says BMW in the pic.)

That’s where you can also get mpg, etc.

There is a mileage read out, but is it "instantaneous" like the little sweeping needle (not like it's very accurate)? I rarely use the OBC and typically only the distance-to-empty reading to plot out gas stops on a road trip.