Fuel economy

lawrothegreat · Apr 28, 2014

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.

CO2slave · Apr 28, 2014

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!

Pintie · Apr 28, 2014

And I am always happy that the speedo reads over. Would be a problem if it was the other way!

MaskedAnkle · May 4, 2014

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.

CO2slave · May 4, 2014

MaskedAnkle said:
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.

davidtheprof · May 9, 2014

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?

texy · May 9, 2014

You cannot judge fuel economy with only doing 30 miles.....
Give it 3 tanks and see how it pans out.
Texy

donnaj1dlh · May 9, 2014

lawrothegreat said:
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..........

GoKart7 · May 9, 2014

This is too mathematical for me

lawrothegreat · May 9, 2014

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.

Washy · May 10, 2014

We are up to about 2000 miles now and we too are seeing somewhere between mid to high 30's on a tank of fuel.

patch · May 10, 2014

My real life experience is 24mpg US (29 UK) with city driving, always in sport mode.

Running in green mode, with the display always "green colored", following all advices, would get me much better figures.. If you run in green mode and the display is grayed, you will not achieve good mpg.

texy · May 10, 2014

I'd like to see some real cooper (non-S) consumption figures. I know I am in for a shock compared to my Dooper (always over 60mpg, however the driving/journey), when I get my petrol, but the fun-factor will offset that ;-)
Texy

Matt · May 12, 2014

just wondering what this thread is about.... being a bunch of hot red blooded male / females, why are we worried about mpg?

i got my mcs to be driven hard... and expect to see about 15mpg on a good day!

lol

ok.. ill come clean... as im running my mcs in at the mo, im getting about 55mpg... thats been over 4 tanks so far.

my 2012 mcs on average (the two years i had it), it averaged 36mpg (uk gal).

GoKart7 · May 12, 2014

I expect to be the worlds calmest driver

(Disclaimer)

TouchUpDirect · May 12, 2014

My first tank I got 26. That was not going slowly and not messing around much with Green mode. I'm currently on my second tank and have used Green mode almost entirely and am at 33.7 mpg. But I've been trying to milk it on this tank. HOWEVER, I live in Los Angeles and never have ideal gas milage traffic. This 33.7 includes lots of freeway stop and go traffic and lost of Hollywood city traffic.

olires · May 13, 2014

It would really help in this thread if people said if they're using British gallons or US gallons and which engine they have

TouchUpDirect · May 13, 2014

That's a darn good point!

Mine is an auto MCS. Still on my second tank, about 270 miles in and averaging 33.6. All US figures and almost completely in Green. Includes lots of traffic and city driving.

blark · May 16, 2014

To share gas milage members should start using http://www.fuelly.com as a good reference for other members to check in on!

Tracks each tank and gives extremely accurate readings! Haven't seen any 2014 Mini's up yet! Give it a try!

palgt1 · May 16, 2014

Does anyone else have trouble filling up their tank ? I've only been to the petrol station twice so far, both times with about 50 miles of fuel still remaining. However, whereas previously in my JCW It would cost me just under £60 to fill up I'm now only able to squeeze under £50 worth and no matter how much I try I can't seem to get any more in. The price of fuel remains the same !!

BTW I was averaging, over a 3.5 year period, 38 Mpg out of the JCW

Fuel economy

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