OK, that makes more sense. Keeping in mind you are still in the break-in period, I think the first thing I would check is tire pressure. I'd shoot for 35 psi all around. Then we'll have to wait to see if that has an impact. The numbers you are getting do seem low, but should probably work on tuning variables before looking for actual problems.

 

Yeah, well, I like to work on making sure my MINI is running properly. An unanticipated, unexplained drop-off in fuel economy is a good indicator that something is amiss and can be corrected before it becomes a bigger problem.

 

Think of it this way, 1 everybody drives differently, 2 the same person dosent always drive the car the exact same way every time they drive (we often get stuck in traffic or get in a hurry). The fuel mileage calculator is programed into the body controll modual with pre set points as a base, and has adaptive values that will change over time based off of the common fuel injector pulse in the ECU. Theese adaptives take time to change (based off of engine starts and total run time) and more often than they can reset, guess what the driving style changes. Dont forget that not all fuels are the same, slight differances in detergants and additives from batch to batch cause different burn rates, throwing off the oxygen sensor readings that set the injector pulse that changes the actual fuel mileage, and we are back to changing the adaptives in the BCM to make the computer work.

There are so many variables that it will NEVER be 100% correct, the computer is just a best guess at best, and is in no way a replacement for the good old gas gauge and some common sense on when to fill up. If yuo dont belive it figgure your mileage out on paper, every time you fill the car up for a month. Gaurenteed it will always have a differance in mileage, and that is what the computer cant understand.

Dont worry it is normal for the computer to be wrong, but it will get closer in time after it builds new adaptives from all the averages.

 

I don't think that it's off that much. You are doing almost the same exact commute that I do most days. We are very close to the same mileage. My car hardly gets warm before I turn it off. I wouldn't worry too much about it.

 

I'm pretty sure the OP is past the point of wanting the OBC to be 100% correct (or even close). He is now hand calculating and that is still yielding mpg lower than what he expected. The issue now seems to be whether his expectations are incorrect or whether there is an actual problem.

 

the "problem" is most likely the driver.

 

DING DING DING... We have a winner!

Until a brand new car averages out and adapts to your driving style, the computer will be way off. And the advertised fuel consumption for the car is an average based off of a car being driven by a machine on a dyno, to show the best possible results, not an actual person that drives anything like we do and not like a wienie.

 

The EPA did change their methodology a few years ago to produce more realistic numbers. Not entirely uncommon to be able to do better than the EPA numbers.

That said, I looked up a 2010 MINI Cooper S and the City number is 26, Hwy 34, combined 29. So the OP's experience does look to be consistent with that, especially considering the city driving being done. With just city driving, seems like the range calculation should come up in the 350-360 range unless some highway miles are thrown in to help improve the fuel economy.

 

The 2011 MCS - which I have - is even higher than that. That being said, I did check tire pressure today as you suggested and all four were around 40psi +/-. I brought it down to 38psi all around as the manual recommends. I reset the TPMS and will see what kind of mileage I get the next couple of weeks.