Oh okay. I just realised yesterday that it continues to compute and changes slowly. It seems mine is always saying 11mpg.

 

I reset the trip computer every time I fill up with gas. If you don't reset it for a long time, the average is less accurate to tell you how the car is performing now. I guess it's just a matter of what information you are looking for. Are you looking for the avg over the past year? Or the past 2 weeks? Throw a few road trips to Vegas (or where ever) in there and I bet you those numbers are quite different. For me, I'm more interested in how my car is performing currently with the type of driving that I am doing this week.

 

About 18,000 miles on my 550i and I get about 17 mpg combined city/highway and about 24 mpg highway only (75-80 mph). I really don't drive just city enough to have a feel for the mpg.

 

Brand new 550i here, 1500 miles so far. 19.5 mpg (hand calculated based on fuel consumed), at average speed of 35 mph. Except for today's trip, most of the miles have been slow-and-go or stop-and-go Seattle traffic. I did just complete a two-day road trip averaging 75 mph through eastern Oregon and Washington, got 22.9 mpg. I expect I'll pick a few mpg's as it breaks in. On the other hand, now that I am past the magical 1200 miles, I'll probably be in S and M mode more frequently.

Side note, I did test out the M mode a bit on the windy road from Arlington to Condon, both ways yesterday. What a tight flat handling sprinter this is! Love the handling. I DO have to get that V1 wired in though, was worried about the Gilliam County deputy the whole time!

Cal

 

The longer you go without resetting the average, the less affect a change in driving style will have on the average.
Since there are 2 counters (Onboard Info & Trip Computer), I leave the Onboard Info alone. It is the average since I bought the car (20.5). I reset the Trip Computer average evey tank or at the beginning of a trip. It is a better indicator of the recent gas mileage.

 

On the question above, about the metric the "energy control" gauge is monitoring, I think it's intake vacuum.
Cal

 

I would think a car like this would be far more advanced than to use vacuum to measure anything. I'm guessing it's actually a calculation of fuel flow over distance travelled.

 

Just another observation. I bought my 550 about 10 days ago, the first tank of gas averaged 17.4 mpg. 6 speed. It has less than 300 miles on it, so we'll see about how it develops. As a comparison of my driving style, my 2001 330 with a 5 speed that I just retired averaged 27-28 mpg.

 

You might be right, certainly that calculation is driving the results being accumulated and displayed in various places, but the vacuum gauge has been used by BMW for a long time -- maybe not now, but in the past for sure. And, for whatever it's worth, those displays correlate pretty well with hand-calculated economy over long distances at constant speed.

There are BMW Techs on the forum, maybe one of them will tell us what that gauge is displaying...

I agree with someone on another thread, however, that all of the options for displaying instantaneous and cumulative fuel economy is like overkill, a waste of space and increase in clutter. I'd give any number of them up for an oil pressure or water temperature display!

 

I don't neccessarily think its all just about the MPG...but what I would like to see is greater range. A 1.5-2.5+ gallon larger tank would do the trick for me.