535D, LCI, economy - remap needed?

[x12yhp]

Hi Guys,

I got an LCI 535D a couple of months back. Having spent two years getting well above the stated economy of my old skoda, I assumed that I shouldn't have too much bother hitting the 40mpg mark that BMW quote. My regular driving style is very relaxed, most of the driving is done at 60 (not 70) on a motorway. Unfortunately, I struggle to get much above 30mpg. To be totally honest, I cannot even get 40mpg on a motorway trip at 50mph so I am starting to think that I might need the car looked at or remapped. What do you think? With miss daisy driving, should a 535d be able to do that 40mpg number?

Thanks

[x12yhp]

Sorry, I think the car is 2008.

The skoda was a superb 2012, 170BHP diesel. It supposedly will do 60 mpg and this is what I got over 20k mileage. On a 60mph motorway run, I would easily get 65 and sometimes in excess of 70mpg. So it annoys me immensely that the same driving style cannot get anywhere near to what BMW quote. I can be very confident that it IS possible to get the numbers quoted by Skoda so I am inclined to suggest, given my experience and what people are saying, that BMW are talking through their backsides.

I had hoped that the 535D would be a great fun car which could still be frugal (according to the stats) on the motorway. From all that is being posted here, this seems not to be the case. I suspect it won't last all that long in my garage and I don't know I could believe any future BMW stats.

[x12yhp]

Welshbeef said:

Given it shows the "Real mpg" as 36 its what he I'd getting.

Except I am not getting anywhere near 36. I have about 2/3 of my driving at 60mph on motorways and, over the 2k miles I have had it, I am not even getting 30mpg. On the drive back with the car, motorway at 60mpg for about 200 miles, I would only just have got 36. So it feels to me that I am well out...

[x12yhp]

Welshbeef said:

Get to the M way when engine is up temp reset the trip cruise control on at 70mph do this on a flat section with no traffic to hold you up.
Report back in the mpg you achieved.



When did you last v max revs? Literally on the limited in gear?

10 miles, at 60, got me about 33.5 mpg. 70mph on the way back got about 31.

I drive in auto mode so likely don't max revs, will try tomorrow.

gizlaroc said:

HAVE YOU CHECKED YOUR THERMOSTATS??


Seriously, if they are knackered the car is over fuelling.

If they are not getting to 90ºc your DPF will not regen, it will be blocked and causing you to use more fuel.



Just search youtube on how to check, it takes minutes to do.



http://www.bmwland.co.uk/forums/viewtopic.php?f=5&...

I have not done so but will do now.

I called in with my local BMW and discussed but they werent much good. There aren't any fault codes and they pretty much said that this means there is unlikely much they could do. Best they suggested was trying BP instead of sainsburys fuel. I mentioned the thermostats but the guys said this wouldn't be it because the car would then be running somewhat poorly - which it isn't - so is this likely nonsense to get rid of me?

Thanks

[x12yhp]

gizlaroc said:

Jesus wept, and we are meant to be paying these tts £120+ an hour?!!

A fking joke!!

Yes, I know. I will do the temperature check in the morning and see how it goes.

To be honest, the car went through a health check and they pulled up an oil leak which had been missed by the dealer who sold it (which set me back the better part of £500). If I find that the temperatures are way off - a simple check that even I could do - I'll be having a really big go at them for a half assed checkup!

[x12yhp]

Ok, coolant temp got to 81 after my 12 ish mile motorway run. It was slow in getting there and I suspect it might go further on a longer trip...

[x12yhp]

So take it 25 miles and I got to 88. It does take a heck of a time and really it is going to be rare that I drive much more than 25 miles at a time, so that suggests the car just isn't at operating temp for my driving. Does that mean I'm stuffed? Stuck with trying to trade across to a 520d?

[x12yhp]

Got it to 83 after 10 miles 50-60mph. Then 13 miles home with the trip computer reset. Cruise control at 70mph, average speed 70mph and economy approx 29.5mpg. Utter crap. I get better than that from my 20 year old 911.

[x12yhp]

Vee said:

Get your thermostats changed !
Mine was doing similar about 3 months after I put pattern ECP stats on it (initially all was fine).
CPC had a look whilst fixing an oil leak and recommended changing to BMW ones.
The ECP pattern part, when closed was still letting coolant through as the cheap materials inside had distorted. I think the the times I did see high 80's temperature was the car trying to regen - aside from that it ran at mid 70s.

Consensus is that these engines should quickly get to mid 80s - certainly within 15-20 mins of starting.

But my numbers on the temperature don't seem to be that far from expected. It does reliably get to the mid 80s, it will get higher with time and the only minor concern is that it seems to take a bit longer than expected to get there. Others are reporting temps about the same as mine, with good thermostats. What about my info makes you convinced that the thermostats are duff?

Are BMW engines just slow to get to temp and economy?

[x12yhp]

Thanks guys.

I will get to a specialist over the next couple of days and get them to sort it. Since BMW were un-interested, I will not bother with getting them involved.

I'll report back.

[x12yhp]

Another quick question... When I got the car, BMW did a health check which indicated that there was an oil leak. This needed two gaskets changed which included other bits to the effect of intercooler and crankcase breather. Now, I had not had the car so long so I cannot be sure but it feels like the economy got notably worse straight after this... is that plausible? Whilst asking, would checking something like the thermostat operation not be something they should have checked out?

[x12yhp]

gizlaroc said:

But what the OP has to understand is the official combined and urban figure is based on an average speed of 39mph, do any other speed and official figures mean nothing.

I understand that these figures are somewhat difficult to replicate. However, the economy I am getting (less than 30mpg), which is mostly done at 60mph on motorway with only the first and last mile being in slow traffic, is less than BMW quote as the urban figure. However you argue it, it would be totally unacceptable that the car cannot achieve the quoted urban economy, on a motorway trip.

For reference, brim filling over the last week (admittedly I have been doing 70mph, to try to get temperatures checked), indicates that I am getting nearer 25mph than 30mph.

Ken Figenus said:

It DOES - its like the bargain of the century - well over 400 Lb Ft and 40 mpg at 75 :-)

That was why I bought it.... doh.

Welshbeef said:

IF he has averaged >60mpg over 20k from 2ltr TDI 170bhp that's an incredible result and should mean he frequently sees 80-90's mpg on motorway averages to negate stop start city driving cold engine driving congestion driving etc. Possible.


A chap I work with I asked the other day about his mpg he quoted he gets 55mpg out of a 3ltr Jag diesel XF, I was surprised at how good it was and then went into the cold start and mpg to get to the M way at which point he clarified oh no I just reset it for the motorway not interested in door to door... Oh so the 55mpg isn't the actual mpg the car does then is it, well no I guess not ?!!!

The economy was good but part of the point I was making was that my normal drive is really not a strain for the vehicle. Yes, I start cold, but going to work means less than 1 mile in town which rarely takes more than 5 minutes, and then nearly 12 miles on the motorway. I am straight into the work estate so no traffic at that end. Driving the motorway at 60mph and the whole thing should setup for superb economy. So, surely, if I can get good economy (relatively speaking) from the Skoda, surely I should be able to get similarly good relative economy (accepting that this is not, absolutely, as high as the skoda) from the BMW.

Anyhow - update is that I spoke to one local crowd and they were not really convinced that the thermostat was the problem. He reckoned that it would probably be £200 for very little chance of improvement. He reckoned that 30mpg wasn't at all unreasonable. I am going to contact someone else today. I am not looking to get 50mpg, I am not really even needing 40 - but even to jump from 25 to 35mpg is likely to save me £1000 per year.

[x12yhp]

Ken Figenus said:

Yes and that is why people are trying to help you and bothering to give you real world stat readings and other 535d's real world mpg figures etc. Whatever.... doh.

Edited by Ken Figenus on Wednesday 17th December 10:10

Have you some issue? I've said already what I am doing. I have said what mileage I am doing. I've said I am driving 1 mile in traffic vs 12 at 60 on the motorway. I've said that, for the same trip, my old skoda easily got the quoted mpg. I've given as real world as possible and we concluded, some time ago, that there was something up. The car is booked in with an indi and we will go from there. So where is your issue?

[x12yhp]

gizlaroc said:

But also, you had work done and then mpg dropped.

I would be taking it straight back and getting them to look again at their work.

The work was done at the same time that the winter hit. I can't really be definitive. It's hard to demand they fix it when you can't be confident that they caused an issue. Moreover, when they are adamant that nothing about the job could explain poor economy, you are stuck. Fwiw, both the indis agreed with this.