Since I had the engine update installed last October, my trip computer went from 31 to 33 MPG, to 24 to 25. I figured that the engine update decreased my mileage. I have filled my tank 'to the brim' for last 3 tank-fulls, and I calculate 31 to 33 mpg. My trusty trip computer registers 24-25. It could be that my trip computer has a learning delay in math, and I could see about getting a tutor for the summer...

Have others noticed that their trip computer is math challenged? Is it off as much as 8-9 mpg? Is there a fix for this through mini? If not, does anyone have the name of a good math tutor?

Thx,
Steve

 

Both our MINIs trip computers show 2-4% low mileage. At most 1.5 MPG. Nothing like your 8-9 MPG.

 

I've noticed that mine MPG indicator is usually off 3-5...reads 30.5 and actual is 35 most often ('11/02 build MC, unsure if the CD31 has been installed or not, but more than likely)

 

Mine (MCS) is a heavy over-estimator.
Weekend trip to NH and back - all clear roads and steady 75 - the trip estimated 34+ and I calculated about 31.
Previous fills have all calculated at 26-27 with the trip claiming 30+.

It is very surprising that such a simple math thing can be so wrong. I get the impression that the trip does not calculate by counting miles & fuel and doing a divide; instead I think it maintains a rolling average of instantaneous miles/fuel which can be badly thrown by a few miles of overly good or bad mpg.

 

At the risk of offending, are you resetting it between tankfuls? Hold the button down until the display clears. If you're not obviously then it will average over several tankfuls, with predictable results.

Mine is optimistic for a given tankful by about 2-3mpg.

HTH,

Jeff

 

Interesting question.
2 issues here: overall OBC accuracy in reporting mileage, and whether there are changes in this with time.
Overall accuracy: many have reported - especially on the other boards - that mileage accuracy tends to be off quite a bit, and generally mileage is reported as much better than it really is.
When I first got my 03 MCS, i was getting an indicated 25-28 mpg city and 33-34 hwy. This has stayed more or less constant, until I went on my current and continuing roadtrip. Driving from TX to WA over 2500 miles, the indicated mileage steadily dropped for highway driving. I started off with an indicated avg of 37 mpg (way higher than actual), which - without resetting the avg until end of first 2500 mile leg - steadily dropped to an indicated 31 mpg. Things that changed while driving:
speed (started at avg of about 65-70 mph, up to peak of about 75-80 mph, back down to avg of 70-75 towards end of trip.
gas (maybe?), started at 91 past 93 ending at 92 octane gas in WA.
I'm not sure if they still use alcohol in gas here in WA?
Also flat driving at first, then mountains.
Now that I am in WA, my indicated city mileage is way below the indicated mileage I got in TX.
So, bottom line is, indicated mileage has decreased and gotten a little closer to actual, but my actual has also significantly dropped from TX to WA.
I'll keep track of this and will watch to see if the mielage goes back up as I return to TX.
Cheers,
Markus

 

I check the computer mileage with the actual mileage and reset the computer at each fill-up. My MINI's computer is extremely accurate. I was very pleasantly surprised.

 

Same here. Mine is very accurate.

 

Having only run two tanks full of fuel thru my MCS so far I am actually getting optimistic readings from the OBC. I will discount the first tank of fuel as I don’t know if the selling dealer had filled the tank to the top, but my second tank full was actual mileage of 25.5 and OBC showed 29.4. The MCS is still an improvement over my Chevy 2500HD truck at 10 to 12 MPG and the MCS is a lot more fun to drive!

 

>>I check the computer mileage with the actual mileage and reset the computer at each fill-up. My MINI's computer is extremely accurate. I was very pleasantly surprised.

how do you reset it? or is that in the manual and i just didnt catch that.. sorry if this is a stupid question...

 

>>I check the computer mileage with the actual mileage and reset the computer at each fill-up. My MINI's computer is extremely accurate. I was very pleasantly surprised.


I agree with kensmini :smile:

I also reset at each fill up and my manual computed mpg is within .5 mpg of what the OBC is giving me.

 

My OBC seems to be off by 2 mpg. It registers at 29 mpg and I calculate 31 or so. I was relieved that it wasn't off in the other direction.

 

>>>>I check the computer mileage with the actual mileage and reset the computer at each fill-up. My MINI's computer is extremely accurate. I was very pleasantly surprised.
>>
>>how do you reset it? or is that in the manual and i just didnt catch that.. sorry if this is a stupid question...

It's in the manual and your MA should have shown you...but, press and hold the selector button while you are looking at the MPG readout until it clears.

 

>>>>>>I check the computer mileage with the actual mileage and reset the computer at each fill-up. My MINI's computer is extremely accurate. I was very pleasantly surprised.
>>>>
>>>>how do you reset it? or is that in the manual and i just didnt catch that.. sorry if this is a stupid question...
>>
>>It's in the manual and your MA should have shown you...but, press and hold the selector button while you are looking at the MPG readout until it clears.


((((Thanks!!! I NEVER had ANYONE even mention that the computer could be reset!!! I have told my MA, technician, and service manager about the change in mileage on the computer since the engine upgrade, and no one even thought to ask if I knew about resetting the computer!!! YOU are GRRReat!!! I'll reset it tomorrow when I fill up and let you know what I find. This is alot easier and less expensive than getting a math tutor. The high school teacher I know will be relieved too. She looked concerned when I said that the arrangement would involve her tutoring my car-- although she did offer to borrow the keys and teach the car to how to add 1 to the current number of drivers...
Anyway, 'tanks alot' for your help!!
Steve))))

 

I have to admit, I'm spoiled by the VW's trip MPG computer. The MINI "computer" pales in comparison. It doesn't have an instant MPG setting, it seems to "skip numbers" drastically even after 200 miles of driving & it doesn't have a longer/short term setting like my VW. Ian, I think you are right, the computer is calculating the delta's in some short term avg which can be skewed very easily. Having said that, I still love my MC but perhaps the MCS's MPG isn't that bad after all! :smile:

My 2003 MC has 2500 miles on it now (healthy usage after 2 months) and I avg about 20 mph resetting after every 2 full tanks. My MPG is 23mpg which is considerably lower than the 28 estimated by the EPA. Seems like the only way to base line the MPG numbers from this site is to chart MPG with AVG speed from the computer (think avg speed is accurate)

Consumer reports rates the MC at about 30 mpg overall. I wonder what it rates the MCS? :smile:

 

My computer reads TOO HIGH ! ! !

When I get 26 actual MPG it'll read around 29 MPG.

Once I got 29 actual MPH and the computer read 33 MPG.

I base my actual MPG on the digital odometer's mileage readout. Could it be that the odometer is incorrect and the computer's MPG is true??

 

If I reset the computer at fill up and reset the odometer at fill up... the numbers are very close. Especially when you factor in did you get the car completely full this time versus last time etc. So the key is to reset both and I do it before I start the car. I just turn the key to where it would turn the ignition and don't depress the clutch so everything is on and ready then I reset both then start the car. I have an S with 1850 miles. I drive in a short shifting style normally. IE I tend to shift at 3000rpm or less, and I am not routinely downshifting and using the engine to brake the car. I am getting during mostly highway driving about 31.5 and the worst during mostly city driving is around 26mpg. I do not always drive in this manner. I occassionally find a nice stretch of road and drive like a madman. My highest tank so far has been 32.1mpg and my lowest was just under 26mpg. So, I am happy with the fuel economy. I didn't buy this car for fuel economy; I bought it for fun, and the fuel economy has be a very pleasant surprise!

jc

 

My computer reads 3 mpg higher than I actually get. It seems mileage on my MCS drops off relatively quick when I exceed 70mph.









Gary in Duluth

 

jurni,
>>My 2003 MC has 2500 miles on it now (healthy usage after 2 months) and I avg about 20 mph resetting after every 2 full tanks. My MPG is 23mpg which is considerably lower than the 28 estimated by the EPA. Seems like the only way to base line the MPG numbers from this site is to chart MPG with AVG speed from the computer (think avg speed is accurate)
>>
When I had an MC, I was getting a convincing 31-32mpg by calculating from the fillup (US gallons).
Then winter came - and I also had a software update - and mpg dropped to 28-29.
But my average speed is about 30-35mph, a little higher than yours. That probably influences the mpg too.

Biggest thing I find is how heavy footed you are. Doing the same journey daily, I can easily get the trip computer to read around 32 or around 35; of course it is wrong both times, but it must be registering some real difference in fuel consumption.

You could try one gas tank driving very economically - gentle acceleration, coasting to a stop instead of hard braking, speeds below 70, etc.
But then your lift might be dull :smile: