V6 Diesel software update recall

[ColinMerc]

They reset everything including gearbox so exact figures unknown, as you say could be the winter conditions etc...Took a week for it to settle back to my style. Long run from 49 to 42mpg using obc, around town 19mpg. Cheers

 

[Bellow]

The only thing to note is also that the diesel in stations has probably recently switched to winter diesel, and the outside temps are a bit colder, so a MPG decrease should be expected. But as much as I'm seeing, I don't believe.

Crossed my mind also but there's an earlier post where someone had their car done in June and is suffering poorer mpg.

 

[mercmancdi]

Off the point , but do stations change there fuel for winter ?

 

[Petrol Pete]

Imagine if a commercial aircraft manufacturer told BA or Etihad that the next engine service they have done will reduce performance by 5% while at the same time increase fuel consumption by 15% ? within moments the airline would realise they would have to carry less passengers/freight and charge more and they would not be able to reach some of their scheduled destinations due to revised fuel consumption.

A few hours later the aircraft manufacturer would be facing a billion dollar lawsuit (which they would lose) and go out of business shortly afterwards.

 

[st13phil]

Off the point , but do stations change there fuel for winter ?

Yes.

"Summer" diesel is prone to gelling at -4c and below, so filling stations are required to swap over to "Winter" diesel which is more resistant to cold but has a lower energy value per unit volume than summer diesel. The swap over points for the mandatory supply of winter diesel from filling stations is from 16th November to 15th March inclusive, as defined by British Standard.

 

[Gazwould]

Does the splash of petrol in a derv help at all ?

 

[st13phil]

Does the splash of petrol in a derv help at all ?

No - unless you want to trash the injection system.

 

[Gazwould]

Lol , alot of derv owners already put petrol in to clean the injectors etc .

 

[190]

Off the point , but do stations change there fuel for winter ?

As has been said they do, both Diesel and petrol have lower calorific value. On top of that there is increased aerodynamic drag due to colder air which for motorway users can be a bigger effect than the fuel. Add Increased warm up times and heavier traffic and a 10 % reduction in MPG is possible even if most don't see such a big effect.

 

[st13phil]

Lol , alot of derv owners already put petrol in to clean the injectors etc .

Whether they do or not, it certainly isn't good practice for Common Rail or Unit Injector systems.

 

[rtfm]

I believe modern Diesel engines also have fuel line heaters to avoid gelling?



Sent from my iPhone using Tapatalk

 

[Gazwould]

Whether they do or not, it certainly isn't good practice for Common Rail or Unit Injector systems.

Petrol..

 

[Bellow]

Does the splash of petrol in a derv help at all ?

Nope. In cold weather a diesel craves cetane - not octane.

It might help curb the waxing - but not really needed these days.

 

[Gazwould]

But does the petrol act as a catalyst reducing diesels inherent ignition delay thus increasing Cetane ?

 

[TeddyRuxpin]

I'm going to buy a new thermostat today to rule that out. Don't want to look like a muppet when I take it in.

 

[Bellow]

But does the petrol act as a catalyst reducing diesels inherent ignition delay thus increasing Cetane ?

Doubt it. Octane is the measure of 'ignition delay'.

 

[Petrol Pete]

A mate of mine has been adding 2 stroke motorcycle oil in the tank of his transit vans for years , both the older versions right up to his newest 2018 van.
He swears by it and is convinced it has helped him avoid breakdowns that others have suffered.

The older engines would have probably run on a mixture of diesel/cooking oil and heating oil without blowing up, not too sure how modern diesel engines cope with oil being added but appears to have done his vans no harm ...or good ??

 

[TeddyRuxpin]

Given the relative lack of uproar and people moaning, I have to ask - are there people who have had their OM642 updated and *haven't* noticed a decrease in average MPG?

 

[Gazwould]

Doubt it. Octane is the measure of 'ignition delay'.

Almost , 'octane' is a chemical and the measure of 'ignition delay' is milliseconds .

 

[wongl]

My W205 is going in for its 3rd service soon (on a service plan to the MB dealership in Croydon, a Mercedes Benz owned dealership as far as I know). Has anyone successfully decline the firmware update at the dealership? Will this invalid the MB extended warranty?