BMW 123d economy question, any owners/testers?

matt100

matt100

matt100

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There's a sort of depressing inevitability to all this but here goes...

I switched my 320d msport coupe of a 123d msport 3dr about 2 weeks ago, largely because the 320d had started to get under my skin with niggles like a rattle I couldn't find, a scratch on the door, brake service looming etc.

I know none of those are good reasons to change car but thats not the reason for the thread.

Then I found a local bmw garage that had a white 3dr 123d which solved another issue I had with the 320d, that was pauper spec (cloth/alcantara, no nav, no BT etc etc) in that it was pretty much fully loaded.

So I did the deal and now it's mine, my taste (or lack of it) isn't relevant here either!

So here's the issue, I do a lot of motorway miles and I get plenty of chance to amuse myself with my MPG. I don't drive around at 55mph or anything I just like to try and eek out as much as I can whilst making decent progress so no hard accelerating, speeding up down hills etc.. Sad I know but it's very boring out there!

So the 320d used to empty a tank at pretty much 45mpg every time. When reset whilst on the motorway and then driven pretty much just on motorways (which I do a lot) I've seen over 50mpg on a whole tank a few times.

So I did the same with the 123d to see the difference... 37-39mpg! And nothing I can do, including setting the cruise at 70mpg, resetting the mpg meter and then coasting down an empty M40 will take it over 40mpg.

I just wanted to know if anyone else has experienced this? I know official figures are fairy tales but not getting the urban mpg on an extra urban run has to be wrong... right?

The daft thing is it seems to do about the same in urban as whilst practically free wheeling round the motorways?

Its in with BMW right now with them checking it out but I've been round the block enough times to expect a call saying they've checked it and it's all fine.

And considering I've had it about 2 weeks and reported this within days, is there any recourse to cancel the deal if the thing can't get within about 30% of its published figures?
 
Hang on, are you questioning why your twin turbo 123d is less economical than your single turbo, less powerful 320d?
 
It was mentioned in another thread that BMW like to put about 15 thermostats on their cars so if any of them have stopped working, you won't be getting quite the MPG you expect.

So when BMW ring you to say it's all fine, get them to change all the 'stats maybe?
 
paradigm said:
Hang on, are you questioning why your twin turbo 123d is less economical than your single turbo, less powerful 320d?
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no i would have thought that would be obvious?

You could take out everything about the 320d as its fairly irrelevant except that if I posted up the figures I'm getting with the 123d someone else would say it was down to driving style etc, the point is in 2 cars that have a very similar official figures I am getting significantly different results and more to the point way way off what I was expecting from the 123d when making exactly the same journeys.

I thought it was a fairly useful comparison, I'm not so stupid as to think there won't be a difference, most likely a negative on, I just didn't expect it to be 20% between the 2 cars or, if you want to put it another way 20% off official figures for extra urban or to put it yet another way less indicated mpg on a motorway with everything reset and doing a constant 75 with no braking or accelerating than the official urban figure.
 
s0ck said:
It was mentioned in another thread that BMW like to put about 15 thermostats on their cars so if any of them have stopped working, you won't be getting quite the MPG you expect.

So when BMW ring you to say it's all fine, get them to change all the 'stats maybe?
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yeah I did see there's a way to get your coolant temps as well, apparently that can be a major contributing factor but you have to unlock some sort of menu in the OBC and to be honest, phones, pcs etc I'm quite happy to mess about with.. cars.. not so much!
 
Quite, so just get them to change them all. Job done :p

AT shows 55 combined for the 123d so I'd be wanting to see at least 45 over a tank with motorway miles.
 
various sites saying 45+ I think honest john has it at low to mid 40s, its an auto if that makes any difference to this style of driving?
 
Seems low. You can get that out of a petrol 2.0TFSI (at least i do anyway) on the motorway. Im sure you can get near that in some of BMW's newer 3.0L petrols as well.

I would have thought you would be getting at least over 40.

What bhp does the 123d have?
 
matt100 said:
various sites saying 45+ I think honest john has it at low to mid 40s, its an auto if that makes any difference to this style of driving?
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The auto will make a MASSIVE difference and not in a good way. It's a conventional auto rather than one of the newer types and there are two important things to note about these:

a) When tested for the European NEDC tests, an automatic gearbox is allowed to decide when to change gear whereas a manual must change at a prescribed time. As a result, the test disproportionately penalises manuals against autos

b) A 6 speed torque converter auto will sap anything up to 20% off the economy you get.

Let me guess, your 320d was a manual?
 
Nope, automatic.

This is why its not sitting well with me. I know it has an extra turbo and all that but I doubt thats getting much use at a constant speed in 6th!
 
Looking on Fuelly seems to show around 20% of owners getting sub 40mpg (unfortunately not broken down by transmission) ... seems the kind of economy you are seeing is about right!

If you really aren't happy with the purchase I know a lot of garages are happy to exchange cars after the first 30 days so you could possibly switch to a 118d or 116d if you want more economy :)
 
Tom_ed1987 said:
I would expect at a constant speed/load/rpm for the cars to return similar economy figures. Is the 123d brand new?
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no its 3 years old, properly run in.

unrealrocks said:
Looking on Fuelly seems to show around 20% of owners getting sub 40mpg (unfortunately not broken down by transmission) ... seems the kind of economy you are seeing is about right!

If you really aren't happy with the purchase I know a lot of garages are happy to exchange cars after the first 30 days so you could possibly switch to a 118d or 116d if you want more economy :)
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yeah we may well get there to be honest. I'd probably draw the line at a 118d.. I dunno.. maybe. We'll see. Suppose it depends on what they've got, whether they find a fault and how much of a fight they put up which I expect will be a lot.
 
rather predictably I've had a call saying they're part way through testing and have found nothing... ugh here we go...
 
Gribs said:
This is your issue. Work it out properly and it's likely one over read and the other under reads. Car displays are only really useful for showing a change to the norm rather than giving accurate values.
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You say this, but in every car I've had that has average MPG figures displayed by the OBC (5 so far), it has tallied up to what I've worked out manually (or at least to within a few %).

Certainly accurate enough that I'm not going to waste my time calculating it manually and recording my mileage and fuel refills.
 
yeah I can't imagine it's going to be 20% off..

anyway, long chat.. bmw are lining up to do absolutely nothing as I suspected. I'm having a really hard time being direct enough with these guys so they realise I'm serious..

It went in with a bunch of niggles (remember I've only had it a couple of weeks so it's gone back with every tiny thing I can find) and they said "have they fixed the aux port?"

Well yes but in context that's somewhat irrelevant.
 
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