Fuel economy - 2015 Mini Cooper Forum
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post #1 of 183 Old 04-28-2014, 02:53 PM Thread Starter
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Fuel economy

Last week I managed more than 60mpg (UK gallons, 50mpg US) in my F56 MCS at around 50mph on cruise control for nearly fifty miles.


However as this was what the OBC reported, I decided to measure it's accuracy pump to pump to get a real feel for the car. Here's what I found:


Distance covered: 264 miles
OBC fuel consumption: 33.3mpg (lots of traffic)
What I put in the car: 36.65 litres (8.07 gallons in the UK)
Actual fuel consumption: 32.7mpg


That is pretty close....


The on board speedometer is accurate as well - over reading by between 0.7mph and 1.3mph at 60mph using a separate GPS device.
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post #2 of 183 Old 04-28-2014, 03:21 PM
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Thanks for that , it's good to know that the data from the obc is pretty accurate. I don't tend to trust the accuracy of fuel level gauges and prefer to mentally work out the range based on mpg but it seems like the boffins at BMW have done their job. They need to pass it on to Toyota as my hybrid fuel gauge shows empty when I have nearly 2.5 gallons left in the tank!

Speedo accuracy is good too!
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post #3 of 183 Old 04-28-2014, 06:44 PM
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And I am always happy that the speedo reads over. Would be a problem if it was the other way!
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post #4 of 183 Old 05-04-2014, 07:55 AM
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My MCS needeed its first fill up:

OBC showed 38.6mpg.
My calculations make it 33.93mpg.

I thought the OBC was being terribly optimistic! That's a mix of sport, mid & green modes, covering 244 miles, never exceeding 4,500 rpm.
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post #5 of 183 Old 05-04-2014, 08:29 AM
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Originally Posted by MaskedAnkle View Post
My MCS needeed its first fill up:

OBC showed 38.6mpg.
My calculations make it 33.93mpg.

I thought the OBC was being terribly optimistic! That's a mix of sport, mid & green modes, covering 244 miles, never exceeding 4,500 rpm.
Is it possible that the tank wasn't fully brimmed prior to this fill up? Or the pump nozzle was more sensitive on this fill up and shut off earlier.? That would be my best guess - the difference between the 2 figures is only 4 litres of fuel. Perhaps you will see the difference in your next fill up. I always try to use the same pump etc. BTW There is a good free iPhone app called Road Trip LITE where you put your mileage and fuel in and it calculates the actual mpg. Then after a few fill ups the average sorts out the differences in pumps anyway.
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post #6 of 183 Old 05-09-2014, 09:49 AM
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Just got a new 2014 Mini (automatic), only done 30 miles or so of city driving, but fuel economy is down around 22 mpg (US EPA rating is 29 for city). Very light foot and mostly green mode. Is there something about first few miles? Engines are already broken in, I thought. Back to dealer?
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post #7 of 183 Old 05-09-2014, 01:01 PM
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You cannot judge fuel economy with only doing 30 miles.....
Give it 3 tanks and see how it pans out.
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post #8 of 183 Old 05-09-2014, 01:44 PM
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Quote:
Originally Posted by lawrothegreat View Post
Last week I managed more than 60mpg (UK gallons, 50mpg US) in my F56 MCS at around 50mph on cruise control for nearly fifty miles.


However as this was what the OBC reported, I decided to measure it's accuracy pump to pump to get a real feel for the car. Here's what I found:


Distance covered: 264 miles
OBC fuel consumption: 33.3mpg (lots of traffic)
What I put in the car: 36.65 litres (8.07 gallons in the UK)
Actual fuel consumption: 32.7mpg


That is pretty close....


The on board speedometer is accurate as well - over reading by between 0.7mph and 1.3mph at 60mph using a separate GPS device.
Am I missing something? I guess your 60mpg is a typo? 50 MIGHT be achievable on a run in comfort mode perhaps..........
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post #9 of 183 Old 05-09-2014, 02:52 PM
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This is too mathematical for me

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post #10 of 183 Old 05-09-2014, 03:40 PM Thread Starter
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Nope no typo, but it's within the range of what is possible.


That is still less than what is claimed on the extra urban run. A couple of things to note:


You don't achieve those levels of fuel consumption easily.


US gallons are smaller than UK ones, which means UK mpg figures look better.


To achieve 60mpg I used cruise control, i.e. I didn't manually use the throttle as invariably this will use more fuel. There was a little slipstreaming in places, which does help a lot. 95% of the journey was at speeds between 50mph and 60mph, not stop start traffic, again this makes a big difference. You waste lots of fuel accelerating and comparatively little maintaining a fuel efficient speed.


I once managed to squeeze 540 miles out a 50-litre tank in a R56 MCS so make no mistake turbocharged engines in small cars can achieve these figures on the limit.


Davidtheprof, I doubt anything is wrong, it's probably a mixture of traffic conditions, environmental conditions and possibly driving style. You don't have to drive aggressively to waste fuel - avoiding braking at all costs makes a big difference. For example when approaching a corner don't brake, instead start coasting in advance to lose the desired speed instead.


Just on a point of clarity I do like driving properly and seem to be averaging mid-thirties at the moment.
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