[darylrese]

So another fill up in the 320i and my mpg has dropped slightly to just 31.8mpg.

Every trip i do says 34 - 36mpg and average onboard says 32.6....i think the OBC is a bit optimistic!!!

[duvetdo]

All OBCs I've had are at least 5% and sometimes 10% optimistic. But they are consistently, so a good enough guide, I'd say. I usually use Fuelly for the first 6 months of ownership to get a handle on the real mpg. Then I get bored with filling it in.

[fatalkarma]

I get 16 to 18 maybe less. Don't care - enjoy the car. If mileage is a concern get a Prius. On highway I don't know what cruising mpg is - always crushing at something much higher

[dangerous_al]

Originally Posted by darylrese

So another fill up in the 320i and my mpg has dropped slightly to just 31.8mpg.

Every trip i do says 34 - 36mpg and average onboard says 32.6....i think the OBC is a bit optimistic!!!

You can change the correction factor for the OBC, I had to change mine and it is better, but a lot of stop starts throws it out

[Greg666]

Not bad for a 335d! Mixture of A roads and motorways

[Trialskings]

Originally Posted by Greg666

Not bad for a 335d! Mixture of A roads and motorways

You left at 1 and did an 11 hour journey arriving 3 hours after you left?
Curious

[Greg666]

Originally Posted by Trialskings

You left at 1 and did an 11 hour journey arriving 3 hours after you left?
Curious

Not the one trip. Commuting over the space of a week

[lobeydosser]

Originally Posted by Greg666

Not the one trip. Commuting over the space of a week

I did think that a 300 mile run at 31mph would be a wee bit boring, right enough.

[Redandy]

More than happy with my morning commute a mix of local roads / 50mph average motorway and appx 3 miles normal motorway.

Was 34.1 when I pulled up dropped whilst parking and it wasn't particularly driving miss daisy at all just with anticipation - same run that did feel very much miss daisyesque in the 420i accomplished 39.9 but boy that was dreary.

Been averaging around 30 most mornings but this was much milder so no heated seats or steering wheel on - can only put the increase down to that.

[Redandy]

Now attached

[Signpost]

Not bad for a 320dED!

[ronime]

Originally Posted by ronime

Only had our 320i xDrive for a week but we are struggling to top 26mpg.

Two months in and our tank average has improved ever so slightly.

We did manage to top 50mpg on a Sunday morning run to the Trafford Centre before Christmas.

ECO Pro mode and an average speed camera enforced 52mph (indicated) most of the way there. 50.1mpg showing on the trip computer when we parked up but this had dropped as the car idled for what seemed an eternity while SWMBO figured out how to use the camera on her Jesus phone to capture the moment.

[ronime]

Originally Posted by PaulBearer

I can see why the 320d exists for economy. But the 320i I'm struggling with.

The 320i exists for the appreciation of peace and serenity.

The 320d exists for those who appreciate the sound of gravel tumbling in a cement mixer.

[JOHNBMWM5]

Originally Posted by ronime

Two months in and our tank average has improved ever so slightly.

We did manage to top 50mpg on a Sunday morning run to the Trafford Centre before Christmas.

ECO Pro mode and an average speed camera enforced 52mph (indicated) most of the way there. 50.1mpg showing on the trip computer when we parked up but this had dropped as the car idled for what seemed an eternity while SWMBO figured out how to use the camera on her Jesus phone to capture the moment.

At 50MPH my 5353D M Sport gives 48/50MPG>

[Blacktemplar]

Just for academic fun I've done a few back-to-back comparisons of Sport, Comfort and Eco-poo modes over the past week: two days in a row for each, exact same 13-mile urban route, same time in the morning, similar weather, traffic density etc. On each occasion, with the exception of Eco-poo I tried as best I could to drive smoothly, no bursts of acceleration, but equally no OAP-driving. In Eco-poo I drove to the 'star' rating, though I only managed 4 stars each for acceleration & anticipation, but only one for (manual) gear-change.

So, what were the results?

Sport
MPG 33.7
Ave speed 19.1 mph

Comfort
MPG 35.9
Ave speed 18.7 mph

Eco-pro
MPG 37.4
Ave speed 18.9 mph

So what does this tell me then?

1. Eco-poo is as dull as death, throttle response is borderline dangerous in some situations. Conclusion: avoid at all costs unless you are (a) Scrooge, (b) obsessed with getting 5 stars on all criteria or (c) a sad git who doesn't get the point of owning a 250bhp BMW

2. Comfort mode is actually OK for stop-start commuting traffic, throttle is sharp enough for most circumstances, though stop-start can be a bit annoying at times.

3. Sport mode is the automatic default and should be what the car starts on.

Based on say. 3,000 miles just commuting, the difference in fuel cost worst to best is only about £45 (based on 8.8gal difference @ £5.09 per gal / £1.12 per litre).

So sport mode it is then.....