[Bash328I]

Okay so this Might sound stupid but How Accurate is the MPG displayed by BMW on the dash..?

I was doing a 900 mile drive and my MPG was displayed in upper 40's The most i got on pic was 45 MPG.

I dont think its 100% accurate but would like to beleive so..

SO again my question...How accurate is it...?

[Myrder]

It showed 20.4mpg on the dash and I calculated based on gallons to fill and previous trip set to come in at 18.7mpg. This sounds about right, I am also running e85 mix so who knows if that would interfere with the computers estimates.

[WreckerX5d]

Mine reads about 1mpg less on average than what I actually get. It has been that way since I have been tracking for 36k miles. Sometimes it is even 3mpg less.

[Efthreeoh]

So, I've recorded every drop of gas I've put in my car from mile 3 (delivery) to 225,000 miles. The data I've done the statistical analysis on is up to 219,000 miles. The average difference between the BC tank MPG average and the hand calculated tank MPG average is -0.23 MPG, which means the computer over estimates the MPG by 0.23 MPG. Considering the variation of fuel dispensing at the pump (I try to use the same pump every time) I'd say the BC (computer) calculation is more accurate and the hand calculation is 0.23 under estimated.

[Wakka]

Originally Posted by Efthreeoh

So, I've recorded every drop of gas I've put in my car from mile 3 (delivery) to 225,000 miles. The data I've done the statistical analysis on is up to 219,000 miles. The average difference between the BC tank MPG average and the hand calculated tank MPG average is -0.23 MPG, which means the computer over estimates the MPG by 0.23 MPG. Considering the variation of fuel dispensing at the pump (I try to use the same pump every time) I'd say the BC (computer) calculation is more accurate and the hand calculation is 0.23 under estimated.

you have 225k miles on your car? jesus man thats impressive

[Efthreeoh]

Originally Posted by Wakka

you have 225k miles on your car? jesus man thats impressive

225,643 to be exact.

[Nkc]

-1km/L difference from my app which is around 10%

[fuddman]

I find the computer calculated mpg to be very close to what I, at times, hand calculate. I've come to trust what the car is telling me; but, I check on it every now and then.
In my car there are two mpg displays, one on the dash (accessible by depressing a button on the turn signal) the other selectable on the i drive. The one on the dash is a continuously running calculation which I can't seem to alter. The one in the i drive can be reset to calculate the mpg over whatever length of time you choose. As you might expect, the two show different mpg numbers.

[melloww22]

Originally Posted by Efthreeoh

225,643 to be exact.

Bravo

[Efthreeoh]

Originally Posted by melloww22

Bravo

I've got the highest mileage E90, confirmed by BMW... just found out yesterday.

[SoCalM235iR]

Originally Posted by Efthreeoh

So, I've recorded every drop of gas I've put in my car from mile 3 (delivery) to 225,000 miles. The data I've done the statistical analysis on is up to 219,000 miles. The average difference between the BC tank MPG average and the hand calculated tank MPG average is -0.23 MPG, which means the computer over estimates the MPG by 0.23 MPG. Considering the variation of fuel dispensing at the pump (I try to use the same pump every time) I'd say the BC (computer) calculation is more accurate and the hand calculation is 0.23 under estimated.

Pretty darned accurate I'd say. I'm on tank two and my hand calc vs the computer are very close as well.

Congrats on the mileage! Would be great to know what you've had to replace besides the standard tires/brakes/oil consumables.

[Efthreeoh]

Originally Posted by SoCalE90

Pretty darned accurate I'd say. I'm on tank two and my hand calc vs the computer are very close as well.

Congrats on the mileage! Would be great to know what you've had to replace besides the standard tires/brakes/oil consumables.

Already discussed it.

http://www.e90post.com/forums/showth...ight=200%2C000

[Malibu1]

How does BMW know how many miles we have on our cars? Does the NSA share that data with them? Just wondering.