Diesel economy on new C220cdi

[se97mlm]

Whats the reasons behind this though. Im baffled. How can something burning more be more effeicient???

For example, having a particulate filter necessitates an extra 2 injections of fuel to heat up the filter to 600 degrees for a purge to occur.

The engines are not becoming more efficient, they are becoming cleaner. fuel consumption and emissions are on opposite ends of a seesaw. If we stuck with Euro 2 we would be able to have much more economical vehicles.

 

[david_e]

Interesting stuff, was not aware of this technology - I always thought along the lines that less fuel burnt meant cleaner engines, and that improved performance was brought about by improved mechanical design - fuel & burn flow, combustion chamber design, engine materials used, injector technology, IT application, etc. As they say, you learn something new every day

 

[se97mlm]

Interesting stuff, was not aware of this technology - I always thought along the lines that less fuel burnt meant cleaner engines, and that improved performance was brought about by improved mechanical design - fuel & burn flow, combustion chamber design, engine materials used, injector technology, IT application, etc. As they say, you learn something new every day

The improved perfomance is brought about by the ability to inject more fuel; torque and injected quantity are directly proportional. Better engine materials and design/analysis allow a greater peak cylinder pressure to be achieved, thus the ability to inject more, ergo more power. Combustion chamber design, fuel flow, injector design and swirl etc influence the "completeness" of the combustion; reducing HC, NOx and particulates. You can have an engine that is very powerful, but belches out black smoke, and that would not look good at all! You could also burn a very very tiny amount and great an awful lot of pollution!

In the engine calibration process, the power curve is checked first; the engine will have been designed to a particular rating. Then all the emissions calibration follows, then all the driveability stuff. The fuel economy that you get in the end is just a function of all this, it's not a parameter that's optimised.

 

[glojo]

Was a 2004 model , so the S211 , it was an EU4 Engine. It replaced an S210 220 CDI EU3

Hi Fuzzer,
I'm totally baffled by this as the EU4 diesel has only very recently became available. Obviously before the new V6 diesel though.

I accept the advertising has been in place but in the real world it was only an option within the last several months! I did not think it was available in the UK during year 2004?

My 2004 S211 320CDI is definitely not EU4.

There is a good right up (new What Car) on the 2.9cdi that replaces the 270cd1 says its more refined than the 320cdi and not much difference in its performance.

I thought the 280 and 320 V6 were the same 'smooth' V6 engine with different mapping?

Regards,
John

 

[Dave Kerr]

I have the new facelift C220 CDI with an auto box and the mpg is useless compared to my '03 manual.
I used to get 55mpg + in the '03 and now I get less then 40 mpg. I did once get 44 on a very long run. 8500 miles now on the clock. The '03 model hit the 50's form day one.

I think just before I bought this one in March someone said why didn't I keep my current car and invest the money "Why didn't I listen" how I hate this car hate,hate,hate....................

Dave

 

[fuzzer]

Hi Fuzzer,
I'm totally baffled by this as the EU4 diesel has only very recently became available. Obviously before the new V6 diesel though.

I accept the advertising has been in place but in the real world it was only an option within the last several months! I did not think it was available in the UK during year 2004?

My 2004 S211 320CDI is definitely not EU4.

200 CDI and 220 CDI have been EU4 in the w211 for a while now , the 270 CDI and in line 320 CDI Have been EU3 untill they have been replaced by the 280 and v6 320 CDI . Thats why they were heavilly discounting the EU3 270 and 320 to shift stock from about november last year.

 

[glojo]

200 CDI and 220 CDI have been EU4 in the w211 for a while now , the 270 CDI and in line 320 CDI Have been EU3 untill they have been replaced by the 280 and v6 320 CDI . Thats why they were heavilly discounting the EU3 270 and 320 to shift stock from about november last year.

Hi Fuzzer,
Spot on, I was only thinking about the S211 and the diesels.

The EU4 spec has always seemed crazy to me as a private owner. When both versions were being offered alongside each other it appeared you were paying more for less. I did not pay much attention to performance, but economy made my eyes bulge! The EU4 is definitely thirstier than the older specification. Is there some sort of tax relief for this newer engine to compensate?

John

 

[se97mlm]

Hi Fuzzer,
Spot on, I was only thinking about the S211 and the diesels.

The EU4 spec has always seemed crazy to me as a private owner. When both versions were being offered alongside each other it appeared you were paying more for less. I did not pay much attention to performance, but economy made my eyes bulge! The EU4 is definitely thirstier than the older specification. Is there some sort of tax relief for this newer engine to compensate?

John

Hi John. I think there is considerable advantage tax-wise for German residents to opt for an EU-4 model, but i think in this country we don't get anything yet... i could be wrong though...

 

[fuzzer]

Hi John. I think there is considerable advantage tax-wise for German residents to opt for an EU-4 model, but i think in this country we don't get anything yet... i could be wrong though...

from what i can remember there used to be before our lovely chancelor removed it in the last budget

 

[Rory]

Hi Fuzzer,
The EU4 is definitely thirstier than the older specification. Is there some sort of tax relief for this newer engine to compensate?
John

The issue is that the EU have made EU4 mandatory from 1st Jan 06. No car can be registered (in the UK at least, presume this applies across the whole of the EU?) after 1st Jan 06 if it isn't EU4.

There's an EU5 coming too (2009?), but manufacturers are saying it's going to cost a fortune to meet it.

 

[smeeeee]

has anyone got any good news?

I have the new facelift C220 CDI with an auto box and the mpg is useless compared to my '03 manual.
I used to get 55mpg + in the '03 and now I get less then 40 mpg. I did once get 44 on a very long run. 8500 miles now on the clock. The '03 model hit the 50's form day one.

how I hate this car hate,hate,hate....................

Dave

Please, can someone tell me some good news about this car, surely someone must be getting better mileage than this?

I've just bought an auto C220 CDI and frankly, 36 mpg is rubbish for a diesel these days, I'm starting to feel awfully mixed about my recent purchase with all the talk of rubbish quality etc.

Should I cancel the order?

Can I cancel the order? It's past the build change date and they have my 10%

boohoo......

 

[glojo]

I've just bought an auto C220 CDI and frankly, 36 mpg is rubbish for a diesel these days, I'm starting to feel awfully mixed about my recent purchase with all the talk of rubbish quality etc.

I know this is no consolation, but the new 220CDI might not be the most economical, and indeed those figures are certainly not that impressive, but.... try to look at all the other plus points.

Going down Telegraph Hill gives a fantastic fuel figure, then when we drive up it, I tend not to look at the fuel consumption. 99.99mpg is brilliant.

John

 

[Rory]

Please, can someone tell me some good news about this car, surely someone must be getting better mileage than this?

I've just bought an auto C220 CDI and frankly, 36 mpg is rubbish for a diesel these days, I'm starting to feel awfully mixed about my recent purchase with all the talk of rubbish quality etc.

I think you'll find that it's not too bad compared to other *auto* diesels (apart from multitronic Audi’s).

I have a C270 and its MPG varies hugely with the type of use. I'm being paid mileage so I tend to drive it like a chauffer. I can get high 40’s on a long, steadyish motorway run, but quick stop / starts, racing from one set of lights to next, will see 30MPG.

My solution it to only use it for long journeys – for local stuff I use my wife’s Jazz, which seems to do 50MPG whatever you do it.

 

[smeeeee]

thanks chaps...

for the encouragement.

It's just that I'm used to getting around 50mpg in my Audi (manual I know). I am looking forward to the comfort/smoothness with an auto but I was hoping for more than 36mpg.

On the plus side, there are lots of hills that I can coast down on the way to work

I'm also sure I saw a thread on here not so long ago, that talked about this as a known problem that MB may be doing something about, it's not been updated for a while though...

 

[Rory]

On the plus side, there are lots of hills that I can coast down on the way to work

I'm *sure* you realise, but just in case: Don't coast down hills, run down them on the over-run. In all modern cars this shuts off fuel delivery completely. You'll find that if you shift into Neutral, fuel is used to keep the engine on tickover. You can also have dodgy moments in cars with engine speed sensitive power steering if you coast.

What surprises me is that I can drive a couple of hundred miles, yet one burst up a hill will reduce the trip average MPG by .1 or .2 MPG. What I try to do is build up speed down hills and then allow it to decay when going up again - but there's a limit to how much you can do this with annoying other drivers.

The big thing in normal driving is to avoid stopping (not always possible, I know!). Getting these cars going again (even the C-Class) seems a big effort.

 

[smeeeee]

I'm *sure* you realise, but just in case: Don't coast down hills, run down them on the over-run.

Thanks Rory, yeah, it was more a turn of phrase rather a literal coast. Besides, not sure what would happen to an auto in neutral down a long hill...

I have to say, this has been the most see-sawing car purchase I've made, their are some very strong opinions out there, positive and negative. I hope I don't end up hate, hate, hating my car

 

[fuzzer]

Thanks Rory, yeah, it was more a turn of phrase rather a literal coast. Besides, not sure what would happen to an auto in neutral down a long hill...

I have to say, this has been the most see-sawing car purchase I've made, their are some very strong opinions out there, positive and negative. I hope I don't end up hate, hate, hating my car

you won't , positives outweigh the negitives.

 

[tamrsoft]

How do you estimate your mpg ???

Interested to know how you all calculate your mpg, do you quote the Trip Computer values or calculate long term over tankful used v. mileage covered. I have 4 year old E220 CDi which seems to get 35-38 mpg on local runs and 50+ mpg on motorway runs averaging 65-70 mph, I have no complaints with this. This is based on Trip Computer figures, (I am making notes of tank fills v. mileage to back these figures up).
I am not sure how the Trip Computers calculate these values or how accurate they are. Does anyone know ???

 

[Rory]

I use the trip meter.

I had to fill up my wife's Jazz yesterday and realised that (unusually) I'd also filled it up last time too. So I calculated the brim to brim MPG. It was 46.6, rather than the 52.2 the trip (since last reset) MPG showed. That did explain why the fuel gauge seems to go down rather faster than the trip fuel consumption would suggest (it's noticeable as the car has quite a small tank).

 

[DITTRICH]

Filling the tank to the brim and mileage from the trip meter counter works for me.
Les