I just did my second fill up today, calculated 33.79 MPG, OBC says 32. Mostly highway. MCS

 

Hi I have a 07 (Non S) the OBC since new indicates 39MPG for the last 1,925 miles, since new. The last tank calculated to 39.58 mostly highway and back roads. Easy driving some coasting. This will be vary if you reset the OBC with every fill up

 

Oh i didn't even think about resetting it at fill up....I have to try that!

 

I reset everything after filling up and so far just 2 times my manual calculations surpassed the OBC reading by 2 MPG but that was highway driving.Local (city) the OBC reads higher MPG though.Keep in mind the OBC is just an average MPG so it will be off.

 

Gee....I don't know!!! I don't ever hand calculate. I just watch the OBC and figure it's more (or less) that.

 

I reset all the time. The OBC is usually 2 to 4 MPG higher than manual calculating. A good indicator, but not accurate.

 

Agreed, it is good for optimizing. Whenever I post mpg #s I take the OBC # and shave off a few...close enough. So if I say 40 mpg here, the OBC says 42 mpg. Either way, this far exceeds my expectation so I'm a happy camper. Besides, I gladly defer any mpg bragging rights to VelvetFoot!!

 

The only time I've seen better than the OBC was in the 04 MC, all the others have been more optimistic, by about 4%. So if you think you're getting 40MPG, you're probably only getting 38.4.

 

Reset at fillup is a very good idea

From what is reported here;
looks like the Computer is taking a 'moving-average' for mileage (as well as speed) and your 'actual-mileage' will suffer more with city driving and all the stops.

That 'Real-Time' (one second update) setting would be most useful in improving your mileage when you can see what 'spirited accelerations'
or extra 10 mph cruise speed is costing.

My inital drive started with several hours of Interstate [75] with a lot of 'High-Torque' 6th gear accellerations from 55 to 75 and coast back to 55,
important for break-in but bad for mileage (AFC was 33mpg). A 'proper' run-in will pay back in spades with better mileage, later in life.

 

I have noticed my OBC runs high on the MPG calculation and my speedo also runs about 5 miles an hour fast at 50. Is there any correlation? Has anyone with a Scan-gauge with a fast speedo verified their odometer?

Thanks

 

I noticed almost immediately that my Highway MPG is between 39 and 42, which is a very nice surprise. I've also noticed that my speed is exactly 5 MPH slower than what the speedometer registers. Someone else had mentioned it and I checked it out during a police speed display

 

lol wow man I enjoyed my last mini too much to even care what the OBC or millage was doing.

 

I kid you not, 39 mpg in my modded S....cant explain it....NOT an easy thing to do, but most definatly possible now