640i bad fuel economy

[tomppa]

So, I just bought 2015 640i and was amazed by the high fuel consumption. Is 19L/100 (=12 usmpg) really normal for this engine, when in city +sport mode, driving relaxed, avg 22km/h? Seems so bad after diesel (335d) 11L/100. Is it like this to own a gasoline car?
Highway seems ok though, 8L (29mpg) at 125 km/h??

I don't know if the engine has been tampered with, supposedly not, but the sound seems loudish, especially cold start is crazy loud - like a straight pipe

[SWFLf10]

Id say that sounds high for that engine. My 535i with the N55 gets around 20mpg city and around 26-30mpg highway. And maybe check around for an exhaust leak under the car. The previous owner could have had an aftermarket downpipe or muffler and swapped it back to stock before selling and it's possible they didn't take care to make sure everything was installed correctly.

Or in my case when I got my car, the previous owner has damage to the stock exhaust pipe and there was a literal hole in it allowing exhaust gases to escape and make the engine sound louder.

[Opie55]

You say you just got it, but "in city" driving can vary dramatically between drivers. One person could do 30 miles of driving in a city and stop 10 times. Another could stop 100 times, and other drivers anywhere in between. Starting these heavy cars from a stop is what really uses up the gas. Then there's the issue of how you start from a stop. Since you use sport mode, I'm guessing you are like me and don't start very gradually. Then there is the issue of sport mode itself, which uses more gas. With all those variables the data is not enough to say anything is wrong with the car. But since your highway mileage seems ok, I'd guess nothing is wrong.

[Alpine650]

I get 17.1 mpg on average in city/highway driving. Frequent user of Sport mode, jack rabbit starts, anf high spped on highway. (650i xDrive, 8 cyl.)

[mudpaw]

I have 75K on the clock and pull down around 19mpg city and close to 30 mpg on the highway.