Real MPG for 20i & 28i

27.7MPG after 220miles. I am putting this down to hills of Edinburgh and the engine being tight!
 
I better get more than 30MPG or I'll be in trouble with fuel costs.
 
Just did a 1500 km trip through Europe on highway.
I was driving light footed did around 130-140 km/h but occasionally I ran into a congested section with stationary traffic. Average was 7.0 l/100 km /40.3 mpg/. The had car bearly 1k in it before the trip.
After my arrival I drove on twisty roads in Sport mode keeping the rev between 4-5k and the consumption on the section was around 13l/100 km /22 mpg/.
 
Second fill up, first calculated fuel consumption.
28.7 mpg-Imp / 23.9 mpg-US / 9.9 l/100km

About 80% town driving 20% dual carriageway and back roads. I've been driving the car very gently.

The computer was indicating 30.1 mpg-Imp. I've reset the computer

Our MINI Cooper on the exact same driving was making 42.2 mpg-Imp.

From the VCA data, I estimated the Z4 would use about 20% more fuel than the MINI. So far the Z is using a lot more than that.

Shell v-power premium in the Z4 and Shell fuel save regular in the MINI.

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I have to admit I'm shocked at how much fuel our Z4 is using.

VCA data for our 2008 MINI is 36.2/61.4/48.7 combined
VCA data for a 2012 sDrive20i is 31.7/50.4/41.5 combined

So according to the VCA, a Z4 should use about 15% more fuel than a MINI. US EPA numbers (not shown) say a 28i should use about 16% more fuel than a MINI Cooper. In the US, the numbers are submitted by the manufacturer. EPA only spots tests a few cars.


So far our real world consumption is about 50% more than the MINI. And the MINI was running on the less expensive grade of fuel too.
 
Maniac said:
You say you use it for 80% town.. Is there time for start stop to kick in on most town journeys?

Yes and we leave it enabled. The last few days have been too cold for Auto Stop.


Our MINI had auto stop/start too.
 
I figured stop start mght have a good impact, perhaps it's over hyped. What do you put the difference down to then? Any difference in routes or driving style?
 
Auto stop has to help. I'm sure we'd be using even more fuel if the engine was idling.

I'm driving the exact same routes as we did with the MINI. I'm driving the Z4 more conservatively than the MINI.

I can think of a few things.

We've been driving with the top down more than up.
Debbie uses the seat heater and I use the steering wheel heater.
As recommended in the manual, we leave the engine idling when raising or lowering the top.
Less than 500 miles on the engine.
The e89 is a larger, heavier car. The fuel economy tests don't accurately take this into account.
Didn't get the tank as full on the last fill. If that is the case, it will average out in the next few fill-ups.
 
I think we need to wait to allow the engine to get bedded in on the 2.0 before we start getting concerned. I have ~ 800 miles on mine and the engine is still extremely tight, it is certainly no where near free revving enough currently to even start to see what a realistic mpg might be. My guess is at least 2500 miles plus to start to see any realistic figures.
I'll keep updating via Fuelly.com so will be interesting how things progress.
 
My 28i is at about 950 miles at the moment and I've been getting 25mpg (US) on strictly city driving. I can't even imagine it getting much better mileage after the break in period. If I reach 27mpg on city, I'd be very, very happy and impressed since EPA lowered it's city rating to 22mpg. :D
 
We did a round trip to Chester yesterday. I filled up early so I could get the highway mileage. -- This tank was about 95% highway.

35.9 mpg-Imp or 29.9-US. This bumped our average on Fuelly way up. It will come back down on the next fill.

The computer continues to give a high number than what I'm calculating. Just before I reset it, the reading was 38.9 mpg-Imp.

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oh dear....

Put my 1st tankful in today having used all the dealer supplied tank.....

Needed 50 litres and had done 309 miles (thats the total the car has done).

Fuelly calculates it at 27.9MPG!!!!! ARGHHHH!!!!

Admittedly, this may not be totally accurate as I don't know if the tank was full full from the dealer, so from now on I know it will be (did 2 clicks of the pump).
 
3rd fill up - 36.2 MPG

34 MPG overall

Going the right way but only 100 miles then I can start to increase the revs so may have an impact on mpg :wink:
 
I'd monitor your usage Keith, as in, which routes you take, how long on each section of road, just for a few days perhaps, as this might explain the issue. If you're driving short journeys on a mostly cold engine, sat in traffic/at lots of lights etc. would be the only real explanation for it.
 
An indicated 33.6mpg for me now. It was 34mpg before the weekend but I went for a sprited drive (first time switching from comfort to sport since I've done over 1000miles) which has impacted the fuel economy slightly.

Started using Fuelly at the last fill-up so should get a more accurate figure in the coming weeks.
 
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