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nashdm2

BMW 520d B47 Engine Fuel Consumption

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Ive just changed from a 2011 N47, F11 520d  Auto over 50k miles I averaged 48mpg  (19" wheels)

 

I now have a 2015 B47, F11 520d Auto with 19's and in my first 1400 miles I'm getting 38.8mpg.

 

I drive 12miles to work, with all but the first two on motorway.

 

If I could put the older engine in the newer car I'd be chuffed to bits !

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Updated:

 

nashdm2 - 2014, B47 Auto,             F11, 18",        8000 miles,   42.3 mpg,

Dave777 -  2015, B47 Sport Auto,   F10, 19/18", 12000 miles,   50.2 mpg over the last 2000 miles, 80% motorway/20% town

admiral -    2016, B47 Auto,             F10, 18",         1500 miles,  42.3 mpg. 

DougL -      2015, B47 auto,             F10, 19"         4500 miles,   40.1 mpg

Peel520d - 2015, B47 auto,              F10, 19"         2550 miles,   42.1 mpg

McFar67 -            B47 auto,              F10, 18/17"  12000 miles,   39.3 mpg, 80%/20% town/motorway split.

Ian_S100 - 2015, B47 auto,              F10, 19"       18000 miles,   42.7 mpg

ExAMG -    2014, B47 Sport Auto,    F10  19',      12500 miles,    45.5 mpg. A mix of country roads, rural A roads and dual carriageway, air con perm on

belboy -                B47 auto,                     17".      11500 miles,    48.3 mpg (did reach 49) generally motorways/main roads

Gordon -               B47                              19",                               tba

Mycos -      2015, B47 M Sport,        F11,             35000 miles,    38.2 mpg. Mainly motorway

Number5 -  2015, B47 Auto               F11, 19"        1400 miles,    38.8 mpg.

 

 

 

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49 minutes ago, Number5 said:

Ive just changed from a 2011 N47, F11 520d  Auto over 50k miles I averaged 48mpg  (19" wheels)

 

I now have a 2015 B47, F11 520d Auto with 19's and in my first 1400 miles I'm getting 38.8mpg.

 

I drive 12miles to work, with all but the first two on motorway.

 

If I could put the older engine in the newer car I'd be chuffed to bits !

 

I think from what I have seen, read and experienced, this 10 mpg gap where the B47 has replaced the N47 seems to be the norm in most cases. This seems also to be the case in other BMW variants where this direct replacement has happened (see my notes on first post in this thread) 

 

Edited by nashdm2

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13 hours ago, nashdm2 said:

 

I think from what I have seen, read and experienced, this 10 mpg gap where the B47 has replaced the N47 seems to be the norm in most cases. This seems also to be the case in other BMW variants where this direct replacement has happened (see my notes on first post in this thread) 

 

 

My overall average for my 2011 N47 auto(none eco pro) F11 on 18"s (17" in winter) is 43.5mpg - it can average high 40's on long journeys fully loaded and low 50's if one up and being really light on the throttle so I am not so sure the difference is as marked as you say.

Edited by E39mad

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1 hour ago, E39mad said:

 

My overall average for my 2011 N47 auto(none eco pro) F11 on 18"s (17" in winter) is 43.5mpg - it can average high 40's on long journeys fully loaded and low 50's if one up and being really light on the throttle so I am not so sure the difference is as marked as you say.

 

Fair comment, appreciated.

 

What I had added in my equation (hypothetically) was that the B47 was meant (on paper at least) to deliver improvements on the N47, so, essentially we should not be looking for parity here as B47 owners against the N47, but, more like an improvement at least I guess.

 

In most cases, new versions of existing engines bring small improvement with each "tweek", I guess with a brand new design, we all had high hopes perhaps.

 

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I am a bit disappointed to read this thread coming over to a BMW 518d after a long list of Fords. Similar experience though with my previous  Mondeos and currently in a 2014 S Max 2.0 Tit X Bluefinned from 140 to 170 bhp. Hard 38 mpg over 40,000 miles. Nowhere near what the manufacturer claims, and whilst the EU rush to regulate on vacuum cleaners and toasters, they do nothing about this scam.

 

The problem is the diesel engine is now in a technological cul de sac, hampered by emissions kit that blunt performance and economy, as posters have found here with the latest versions of their engines. So where is the benefit to the planet of cars using more fuel than before?

 

VW have demonstrated that because CO2 targets are a joke, you might as well cheat than take them seriously. For BMW to claim a 520d will average high fifties mpg when in actual service only achieves low forties, is almost as bad as VW. I guess for tax reasons the 520d looks good on paper, but in reality you might as well stretch to a 530d which can't be far off the same mpg.

Edited by Ram Rod

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Ram Rod,

 

A different perspective:

The test is a gentle drive. It has to be, in order to accommodate weedy cars that can only do a gentle drive. Turbocharged diesels (and petrols to a lesser extent) use hardly any fuel when driven gently (off boost).

Now consider this - you make a 2L diesel, and the max power that is needed for the test is (say) 50 bhp. You can vary the max boost on your 2L diesel so that you can sell it as 150 bhp, 170 bhp, or 220 bhp. But at 50 bhp all the engines are in essence the same, and will all return the same test mpg. But in the hands of the clod-footed general public, obviously the 220 bhp model will drink a load more fuel than the 150 bhp car.

There is no cheating. It's just that the test does not reflect what a typical driver actually does with the car. And nor can it, because there is no "typical driver". And yes, the 6 cyl cars on a gentle drive only suffer a disadvantage equal to the friction of a couple of extra pistons, which is not a lot.

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I think change is coming to reflect real world driving, but at the moment manufacturers can make subtle changes to cars to improve the test mpg.

 

Gaps in bodywork are taped over, tyre pressures raised, low friction oil put in the engine. Even conducting the test in the winter when the air is more dense can make a difference.

 

When my 518d eventually arrives, I will post the fuel consumption here as I always brim the tank and work out the mpg myself.

 

 

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17 hours ago, Pottsy said:

Ram Rod,

 

A different perspective:

The test is a gentle drive. It has to be, in order to accommodate weedy cars that can only do a gentle drive. Turbocharged diesels (and petrols to a lesser extent) use hardly any fuel when driven gently (off boost).

Now consider this - you make a 2L diesel, and the max power that is needed for the test is (say) 50 bhp. You can vary the max boost on your 2L diesel so that you can sell it as 150 bhp, 170 bhp, or 220 bhp. But at 50 bhp all the engines are in essence the same, and will all return the same test mpg. But in the hands of the clod-footed general public, obviously the 220 bhp model will drink a load more fuel than the 150 bhp car.

There is no cheating. It's just that the test does not reflect what a typical driver actually does with the car. And nor can it, because there is no "typical driver". And yes, the 6 cyl cars on a gentle drive only suffer a disadvantage equal to the friction of a couple of extra pistons, which is not a lot.

I agree completely with your points. I would add that the problem with the city pollution targets is not the manufacturers or the present test, but the failure of the city or EU bureaucrats to understand that to estimate the future level of pollution is not possible to use the actual results of the manufacturers test without applying a correction factor to take into account what in this blog is mention as the "real world" consumption. This factor changes from car to car and definitely from driver to driver but on average is of order of a 20% increase CO2 production over the manufacturer test result. The CO2 case is easy to estimate because it is directly linked to the mass of fuel consumed that provides the C12 and the intake of air providing the O16 of the final molecule of CO2. The NOx case is a bit more complicated.

Edited by DarkEnergy

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hi,

 

i've got a late 2015 F11 520d SE auto - on 7,500 miles, 17" standard wheels

 

i'm averaging 47mpg, although after reading this and trying to be ultra careful i managed a 53.7mpg on a 22 mile commute into work the other day - mainly quiet A roads. 

 

observations on my car

 

- using cruise control stops the coasting from working in eco-pro mode. on my normal commute i've stopped using cruise and get around 5mpg better. 

 

- compared to my previous car - the auto brake function on cruise control manes you don't get the benefits of gravity on mpg from hills. ie in my previous car set at cruise, you'd get a bit of overspeed going down hill which would help going back up the next one. 

 

if i'm heavy footed i can certainly see it dip below 40mpg on a journey

 

boshy

 

 

IMG_0108.jpg

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29 minutes ago, Ed Bond said:

Be interesting to see difference between on board computer, short journey,average life (does it reset, my seat does after about 2500 miles) and the brim test, the later being the best. 

 

Mine was over-reading by about 6%, until I entered the correction figure (535d, but I'm sure the optimism is similar):

 

EXCEL_2016-04-17_18-34-44.png.b25a686eff

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59 minutes ago, Ed Bond said:

Be interesting to see difference between on board computer, short journey,average life (does it reset, my seat does after about 2500 miles) and the brim test, the later being the best. 

 

I only ever brim the tank and reset the On-Board Computer at every refill. The variance between the On-Board Computer and the "true" figure has only shown a difference of between 0.3 and 1.1mpg - with the true figure always being higher.

 

I am currently averaging 46.3mpg over 12977 miles - although I have started seeing an improvement recently with the last tank showing 49.7mpg (true) over 458 miles (mainly motorway).

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Has anybody been back to the dealer to complain about the MPG? Have you got anywhere? I'm only on 1,200miles so I can't really give meaningful numbers but the difference from my N47 seems huge! The range just quickly diminishes like its a petrol, my N47 use to last me for ages, even local driving. The range would drop ever so slowly but now I do a 2mils journey and I lose 15-20miles of the range!! Really wounded I gave up my N47. 

 

I I have a friend who's a senior engineer at my local dealer and mentioned it in passing, he says there's not much they can do, MPG is affected by various things and he doesn't think Bmw would investigate too hard. He didn't say it was a known problem

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Would imagine the only thing they can do is a new map which is more efficient - but that could be less power.

 

Having a diesel car from the VW group - yet to see a fix for that little hiccup too!

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4 hours ago, bobbywalrus said:

 The range just quickly diminishes like its a petrol, my N47 use to last me for ages, even local driving. The range would drop ever so slowly but now I do a 2mils journey and I lose 15-20miles of the range!!

 

It might just be that the "range" algorithm has changed between the 2 cars. Range is computed on the average mpg for the last x miles. If the new car has a smaller x than the old car, then the range will do more abrupt drops - especially after a couple of miles cold running (20 mpg or so).

 

I would avoid using the range display to determine mpg. I would do two vaguely scientific things:

  1. With a warm engine, get on the motorway and do at least 30 miles with the cruise control set to 72 (to give 70 mpg real). Reset the trip meter once you are up to speed on the motorway. 50-100 miles would be better.
  2. Each time you fill up, brim it and write your odometer reading on the receipt. After 3-4 fills, work out the mpg for each tank.

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What physical changes are there between the N47 and B47 engines which may be responsible for this reduction in efficiency?

 

How did BMW get the new engines on test to perform better than the previous version, if real time driving shows they are around 20% worse?

Edited by Ram Rod

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Of course the regen process uses fuel which doesn't help. I do a lot of motorway/autoroute/autobahn/autostrada miles and in the 2 years I have had my S Max and 83,000 kms, the DPF hasn't regenerated once.

 

It will be interesting to see if this 518d I have coming will be more economical. I am beginning to doubt it.

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Sorry guys, but I would like to be convinced with hard numbers that in equal conditions the B47 is less efficient that the N47.

I would like to see the result of at least 10 mile flat motorway run at constant 60 or 65 mph, zeroing the trip computer after at least 10 miles running to start the test with a  warm engine and transmission. The test has to be done in a dry and windless day, removing all load from the car, no A/C and normal tyre pressure.

If in this conditions a mileage of at least 50mpg  at constant 65mph or 55mpg at constant 60mph is not achieved with a B47 with more than 5000 miles in the odometer, then I would agree that there is a case to be worried. 

 

Any volunteer?

 

Remember, to save fuel accelerate normally, avoid high speeds and do not brake!! 

Edited by DarkEnergy

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Mitsubishi are the latest company to admit they falsified fuel economy data, joining VW, Renault, Ford, Hyundai..

 

Let's be honest they were all at it, and I have no doubt that BMW know these latest engines use a lot more fuel.

 

May I suggest that, (and I haven't even taken delivery of my F11 yet!, assembly commenced on the 14th April), that we do not just show the loss of economy, but also how much extra it is costing compared to your previous F10/F11 models with the 520 engine.

 

Then we could look at a joint legal claim for compensation.

Edited by Ram Rod

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26 minutes ago, DarkEnergy said:

Sorry guys, but I would like to be convinced with hard numbers that in equal conditions the B47 is less efficient that the N47.

I would like to see the result of at least 10 mile flat motorway run at constant 60 or 65 mph, zeroing the trip computer after at least 10 miles running to start the test with a  warm engine and transmission. The test has to be done in a dry and windless day, removing all load from the car, no A/C and normal tyre pressure.

If in this conditions a mileage of at least 50mpg  at constant 65mph or 55mpg at constant 60mph is not achieved with a B47 with more than 5000 miles in the odometer, then I would agree that there is a case to be worried. 

 

Any volunteer?

 

Remember, to save fuel accelerate normally, avoid high speeds and do not brake!! 

 

 

I do not believe such uniformity would be convincing.

 

It is enough if an owner has merely upgraded to the latest model with a new engine, driving the same pattern and in the same style, to find the car is not so economical as the previous model, but official BMW data shows owners should expect an improvement in consumption.

 

 

A drop of 10 mpg is huge. Company cars will see an extra spend on fuel in their budgets. If necessary a test could be easily set up with identical cars but with the previous and latest generation engines.

Edited by Ram Rod

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Its not just BMW that bring out newer engines that are not as economic as previous, when Honda brought the 8th generation Accord with its newer 2.2 diesel engine, the older 7th generation engine 2.2 diesel was 7 -10 mpg better, the problem is each newer engine has more emissions control fitted to them which in equates  to less mpg but a cleaner so they say a  planet, when I previously owned a 8th gen Accord tourer there were some  owners removing the DPF and claiming instant 10 mpg improvement, because of stricter MOT legislation now they include the DPF any vehicle fitted from new will fail the test if its been removed, I expect they will get even stricter as time goes on with emissions during the MOT. 

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28 minutes ago, Oilburner said:

Its not just BMW that bring out newer engines that are not as economic as previous, when Honda brought the 8th generation Accord with its newer 2.2 diesel engine, the older 7th generation engine 2.2 diesel was 7 -10 mpg better, the problem is each newer engine has more emissions control fitted to them which in equates  to less mpg but a cleaner so they say a  planet, when I previously owned a 8th gen Accord tourer there were some  owners removing the DPF and claiming instant 10 mpg improvement, because of stricter MOT legislation now they include the DPF any vehicle fitted from new will fail the test if its been removed, I expect they will get even stricter as time goes on with emissions during the MOT. 

 

I totally agree with you there. But, why fool the paying customer with seducing figures that suggest it would be better than the previous model. That is one of my big issues with this guys.

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