Software update destroys fuel economy

[MarkJCole]

I bought my B200 D Auto with 5,000 miles & 18 months old. On a long motorway run was achieving 65mpg & easily 50mpg + average on full tank of fuel. I booked a dealer service & received an email the day prior to taking the car in about a software update. The email referred to cars with Ad Blue technology - which my car doesn’t have. I called to query this & was advised it was a generic email & not to pay it any attention. A software update was performed on my car as part of the service & ever since the fuel consumption is at least 20% more. I can’t break 50mpg on a 500 mile motorway journey whereas before I’ve achieved the high 60’s. I returned the car & they checked it out. The dealer said the car was fine & performing as expected. I complained to Mercedes U.K. who basically said the same & tough luck nothing we can do. I asked them to update the software to previous setting but they reckon it’s not possible (I find this difficult to believe). Anyone else had a similar issue. Any advice how to proceed?

 

[MBDevotee]

Really tricky one. Do you have any actual PROOF (rather than what you know) such as mileage logs for work with itemised fuel receipts etc?

You may know this is whats happened but I fear proving it is a different matter

 

[Wearsafoxhat]

Hi,

Lots of threads regarding this update, plenty of mixed options on it too.
Some say that the mpg does improve after a few weeks of driving, a lot are just as annoyed as you...


Sent from my iPad using Tapatalk

 

[Gazwould]

It's world wide , affects other makes of cars and to do with NOx , to reduce NOx you must increase the EGR operation which lowers peak cylinder compression combustion temps so less NOx is produced .

EGR gasses are sooty , hot , inert gasses
( very little oxygen ) and when combined produce an even more incomplete combustion of diesel fuel molecules due to less oxygen causing even more soot and more dpf regens .

Effectively this detunes your engine resulting in less torque and mpg , and a whole host of other negative effects .


Hot egr gasses burning through plastic / composite inlet manifolds .

More soot combining with normal crankcase oil vapour that results in an evil gunk for the egr valve , inlet manifold , swirl flaps and throttle body .

More abrasive soot enters the engine oil causing wear to engine bearings , camshafts and lifters , the plugging of finer oil galleries .

More dpf regens causing higher fuel consumption , diesel striping the cylinder liner oil film and engine oil dilution from diesel fuel wrecking the oils lubricity properties causing premature wear .

Engines should only breathe cool clean filtered air .

It's a wonder why we have an air filter at all as it's eating it's own excrement thanks to the devil valve .

 

[LostKiwi]

The alternative is we continue to pump noxious gas into our breathing air.

Or run cleaner fuels.

 

[Gazwould]

Cleaner fuels are about like E85 .

You seem to forget NOx gets pumped anyway , egr is mearly a reduction device with several negative effects .

I tell people what the gubberment and manufacturers aren't telling people .

And it's not about health , it's about money .

 

[LostKiwi]

EGR is a device to limit NOx.
It's there for a reason. NOx is well proven to be harmful to human health.
It's very clear you have scant regard for regulations and know better than those formulating regulations and emissions control systems.

 

[Gazwould]

Because they are flawed , and we are being lied to .

 

[LostKiwi]

Because they are flawed , and we are being lied to .

Have you thought of offering your services? I'm sure they would love to hear your learned input.

 

[Gazwould]

That's the trouble there's not a full balanced view , very often a bad side to everything .

Let's face it car manufacturers and politicians don't lie....

And misconceptions are rife .

Remember who encounters the most NOx in a city ?

Not who you think would !

 

[LostKiwi]

That's the trouble there's not a full balanced view , very often a bad side to everything .

Let's face it car manufacturers and politicians don't lie....

And misconceptions are rife .

Remember who encounters the most NOx in a city ?

Not who you think would !

And some bloke on the internet has all the answers and can see through all the lies and misconceptions because he read it somewhere else on the internet from some other bloke.

Sorry. I'll believe what the government and manufactures and doctors tell me because they have all the facts.

If they were serious about cutting NOx and PPM diesel wouldn't be available as a fuel for private vehicles but that would create too much uproar from diesel owners.

 

[Gazwould]

Not at all , two very credible sources of the information is a British UK documentary series and the other is an American ex military master mechanic who served in Iraq and Afghanistan .

 

[Steve@Avantgarde]

I dont see how an engine re-burning exhaust gasses and the soot it produces internally is detrimental to its wear and tear. I've been working with MB products since the early 2000s and I rarely see an outright failure of an engine, regardless of the cause. I strip apart Diesel engines fairly regularly, and soot build up is always present in an inlet manifold, EGR or some other part of the induction system, but diesels have always been filthy pieces of kit to work on.

So I am not sure how that part of the arguments stands up to scrutiny.

Of course, these Diesel engines are capable of much higher MPG without the emission control systems that are attached to them, but the trade off is more emissions released into the atmosphere, which needs to be reduced.

So EGR isn't really the devil as its made out to be. Its a workaround to be able to produce Diesel engines to the paying public, of which, the owner of takes a bit of hit at how many times he has to visit the pumps to fill up.

 

[LostKiwi]

Not at all , two very credible sources of the information is a British UK documentary series and the other is an American ex military master mechanic who served in Iraq and Afghanistan .

Then come up with a better method of reducing NOx. It's easy to criticise the existing one, how about recommending a plausible cost effective alternative to the manufacturers. I'm sure they bite your hand off.

 

[Steve@Avantgarde]

I bought my B200 D Auto with 5,000 miles & 18 months old. On a long motorway run was achieving 65mpg & easily 50mpg + average on full tank of fuel. I booked a dealer service & received an email the day prior to taking the car in about a software update. The email referred to cars with Ad Blue technology - which my car doesn’t have. I called to query this & was advised it was a generic email & not to pay it any attention. A software update was performed on my car as part of the service & ever since the fuel consumption is at least 20% more. I can’t break 50mpg on a 500 mile motorway journey whereas before I’ve achieved the high 60’s. I returned the car & they checked it out. The dealer said the car was fine & performing as expected. I complained to Mercedes U.K. who basically said the same & tough luck nothing we can do. I asked them to update the software to previous setting but they reckon it’s not possible (I find this difficult to believe). Anyone else had a similar issue. Any advice how to proceed?

This is a complaint I have heard about too. Might I advise running some fuel system additive through your engine just to make sure your DPF isn't getting caught in a regen cycle draining your fuel Econ.

As for the update itself, you cannot reverse it. The only way would be uninstalling the Xentry software on the machine itself to the reinstall the previous software loaded to the older version, but that isn't possible because once MB update the licence from Germany for the Xentry machine, it won't allow you to go backwards. So you are indeed stuck with it.

 

[bladecrazy]

My e350 bluetec has registered 0.00 on the last 3 mots, very clean for a diesel .

 

[V6Matty]

My wife’s 05 169 just went through it’s MOT and got 0.19 with the EGR and everything else on emissions as standard. So it’s doing thing well in my mind

 

[Gazwould]

Then come up with a better method of reducing NOx. It's easy to criticise the existing one, how about recommending a plausible cost effective alternative to the manufacturers. I'm sure they bite your hand off.

I'm all for reducing it but not at the expense .

There are better ways that already exits , better fuel as mentioned earlier , egr gasses that are taken post dpf and a dpf that is heated up with fuel injected by a 'fifth' / extra fuel injector post engine in the exhaust .

And Adblue double dosing .


You'll be surprised what Steve hasn't seen as there were two items with my own car , one fixed straight forward , and he then experienced it on another car a week later .
Another required a few or third visit and he was completely foxed , then I didn't see it for over 2 months !

Got there in the end

 

[onefortheroad]

I bought my B200 D Auto with 5,000 miles & 18 months old. On a long motorway run was achieving 65mpg & easily 50mpg + average on full tank of fuel. I booked a dealer service & received an email the day prior to taking the car in about a software update. The email referred to cars with Ad Blue technology - which my car doesn’t have. I called to query this & was advised it was a generic email & not to pay it any attention. A software update was performed on my car as part of the service & ever since the fuel consumption is at least 20% more. I can’t break 50mpg on a 500 mile motorway journey whereas before I’ve achieved the high 60’s. I returned the car & they checked it out. The dealer said the car was fine & performing as expected. I complained to Mercedes U.K. who basically said the same & tough luck nothing we can do. I asked them to update the software to previous setting but they reckon it’s not possible (I find this difficult to believe). Anyone else had a similar issue. Any advice how to proceed?

Did this update take place around the time winter set in ?

 

[Steve@Avantgarde]

I'm all for reducing it but not at the expense .

There are better ways that already exits , better fuel as mentioned earlier , egr gasses that are taken post dpf and a dpf that is heated up with fuel injected by a 'fifth' / extra fuel injector post engine in the exhaust .

And Adblue double dosing .


You'll be surprised what Steve hasn't seen as there were two items with my own car , one fixed straight forward , and he then experienced it on another car a week later .
Another required a few or third visit and he was completely foxed , then I didn't see it for over 2 months !

Got there in the end

I never pretend to know or have seen everything...including the weird and wonderful faults your car had.

But if an engine eating its own soot was the cause of engine failures then we would be rebuilding them every week. But we aren't, and neither is any other MB specialist either. In fact we praise MB for their reliability of the mechanicals where diesels easily reach 300k with only minor sub component repairs.