Mercedes C220 CDI Sport Poor Fuel Economy

[Harry Good]

Just returned to the forum after an absence of 6 years and getting an old 124 200TE for restoration and fun. Anyway, on this subject, I was chatting with another Merc owner a couple of weeks ago and discussing the auto box as my old Merc was a manual. It seems that if you drive in 'E' mode, the gearbox will be reluctant to change down when required, so you can end up labouring in a higher gear which was what I noticed and commented on. This is particularly noticeable when driving in a hilly area.
Having started to use the S mode and not tramping on the throttle, it seems to drive better. The box changes down more readily, as I would with a manual and you can hold back with the throttle letting the engine rev freely.
I hope this makes sense. My 1987 124 250D normally aspirated manual, did 40 - 45 mpg, I had a run of 44 miles to work mixed dual carriageway and good B roads. I stupidly sold it at only 300K having owned it from new.

 

[Bob Buick]

Bill,

I also took delivery of a new C220 CDI Sport Auto (September) and am also experiencing poor fuel economy. I'm pretty disappointed considering one of the main selling points was it's fuel consuption. My last motor was a S40 SE lux Volvo (manual) which regularly returned 46 - 47 mpg. So far the best I have seen from the new Merc is 40.6 mpg (most of my driving has been long distance) albeit she has only covered 1400 miles so far.

Bob

 

[Troon]

There are lots of different ideas about how to get the best economy - some prefering to get to cruising speed quickly and others much more gently.

If you're then going to maintain that cruising speed for a significant time (e.g. accelerating down a motorway slip road), it actually makes little difference.

An engine is typically most efficient in terms of fuel used per unit energy produced when at high (but not full) load and around the peak torque rev range (look up "BSFC charts" for further reading). So in theory, a 75% throttle burn down the slip road can be just as efficient as creeping up to speed so long as you're going to drive for far enough to achieve similar overall average speed.

Using 100% full throttle is a different story, though - most engines will do some sort of overfuelling to keep things cool and to extract maximum power. Efficiency drops off in this range.

However, if you're just going between sets of traffic lights in short bursts, you want to maintain as steady a speed as possible. Braking effectively turns fuel into heat (via kinetic energy), so avoid that as much as safely possible. Look ahead and leave big gaps to absorb speed variation.

I think you're getting about as much as you'd expect from a new engine on a short drive cycle like yours. Try a long gentle motorway run to see what you get.

 

[Kingy68]

C220 CDI Sport Auto 61 plate.
Had it a couple of weeks. Driven in Eco mode to get used to start/stop.
From zero miles - Motorway run with A and B roads - average just over 47mpg.
Bimbling around town/village picking kids up/ dropping off and calling in to see mates (so never getting to warm up) averaging late 20's early 30's.
It will soon be doing a few Heathrow return runs and I'll be amazed if its not over 50mpg or more given results so far.
I was hoping it would better the 40mpg (on the Heathrow runs) our current car gets and I'm positive it will do that. Any more is a bonus and once I've established mpg from a couple of tanks with good runs I'll probably never check again anyway.

 

[gizze]

Brabus tuned E320cdi, steady run the other day say on the A12....

Had a short trip across town today from a cold start and my 22 mile trip took over an hour and the car averaged 28mpg.

As you can see, my car has just hit 100k and can still return crap mpg figures on some trips.

 

[Rappey69]

Digging up main road near me so chaos.
Managed 12mpg over 4 miles.. usually 35..

 

[GregW]

FWIW, my 55 plate shows 43.8mpg over the last approx 10k ...

 

[BIGCJL]

I'd say you've got to give it time. 3K is really still running in (loosening up), as it will be till about 50K,from then on you'd probably expect to see "optimum" economy, that said, it will as always be down to how its driven, and on what type of roads.

Mine is a 320CDI, and I average mid 40's, and have touched 52MPG on a run, but my regular journey is 95% m/way, and I notice when driving around town its down to about mid 20's.

All I'd say is, it'll only get better, given time.

 

[Pinenut]

as others have said I would give it time. I have a C220 CDI sport on a 57 plate (pre blue efficiency)and I get 50-53mpg on a long run and 40 to 45mpg as a mix of driving. Short hops in town return around 30 to 35mpg. Mileage is now 43,000 and I bought it at 15,000 miles and the mpg has improved steadily over the miles and also since a major service and new filters oils etc.

My brother runs a 59 plate C220 CDI SE and that has 60,000 miles on and he can achieve 55 to 60mpg on a long run.

 

[survey]

Was considering changing my just pre-BE C class 220cdi Estate. Test drive in a 250cdi with latest 7g+ auto gave 39mpg after approx 30 miles of mixed town and derestricted roads. Then took my car over same route and achieved same mpg. This very disappointing as I expected much more from the new car. Makes me think twice now about changing.

 

[Bob Buick]

Hi Bill,

I bought a new C220 CDI auto Sport in September and like you I am a little (well actually very disappointed) with the fuel consuption (40.6). Albeit according to all the threads it should improve with miles. I guess I'll have to bow to the guys with Merc experience. Having said that I have owned new VWs and Volvos all diesels and they returned well into the high 40s and the VW mid 50s. I would have thought that with all the new innovations and claims of excellent mpg I would be seeing better than I am at present. Here's hoping it improves with age.

Bob

 

[rothbury]

OMG another of these pointless threads featuring the chap with the bigger non B/E engine getting absurdly high figures never ever achieved by anyone else and the mix of dissatisfied B/E users expecting to get more than they actually do. I've said this many times and that is that the 220 and 250cdi B/E engines are amazingly economical given their power and I don' t know why people don't just enjoy them and not pootle about trying to save fuel.

 

[gizze]

OMG another of these pointless threads.....

....that I can't help but read and post in.

 

[Kingy68]

I've said this many times and that is that the 220 and 250cdi B/E engines are amazingly economical given their power and I don' t know why people don't just enjoy them and not pootle about trying to save fuel.

Completely agree. Any engine that can return over 45mpg on a run, 0-60 of 8 secs and a ****** big smile on my face in the process is good enough for me!

I'm monitoring my first couple of tanks of fuel simply to get an idea what it's doing, but I'd already seen enough to satisfy myself economy is something I can just forget about after my first 350 miles as mentioned earlier in the thread.

 

[nrg220]

Mpg

I have a W204 220 CDI auto and its not blue efficiency and mpg has been of interest to me. I would expect you to get that if your repeat local short journeys or heavily stuck in traffic

Example I went to Edinburgh from London and back, average 50.8 mpg BUT I was clocking it 75-80 all the way so didnt hang about

Last week I filled up, reset and drove to Northampton, from Slough ok this time I was doing 60 ish+ up the M40 got to Northampton 61.2 mpg which I was surprised at.

Average I get about 40-43mpg, if I just use to pop down to sainsbury then I get 34-35.

It depends as we all know on how you drive as well but these cars can be very economical, they can also go the other way.

Over the last year I have been pretty level pegging with my Wifes Honda Jazz 1.4 petrol CVT so its quite good. Ive only just past 20k in my 2007 car and bought it last year with 5800 miles on it. Hope this helps

 

[outmyway]

I have a C220 CDI Auto Blue Efficiency estate ... 3yrs old 35K miles ..
I'm also slightly disappointed by the mpg .... but maybe I was expecting too much .....

I cant complain on long fast runs ... any motorway driving at around 70-75mph I can easily average >50mpg .... but around town its typically 30-35mpg on shorter journeys on a cold engine ....

Overall I am averaging around 37mpg ... but less than half my motoring is motorway driving ... its still a lovely powerful heavy car.

I was torn between getting a C350 CDI and got the C220 thinking the mpg would be MUCH better .... but in hindsight I wish I had got the C350.

Over the last year I have been pretty level pegging with my Wifes Honda Jazz 1.4 petrol CVT

nrg220 : Interesting ... I almost bought a new Honda Jazz 1.4 CVT instead of my 3yr old C220 estate (no this is not a joke!) .... I think a Jazz would give far better mpg on urban short trip driving ... plus love the magic seats, but am glad I got the Merc estate!

 

[st4]

The BE's first came out with 5g. Brilliant box but a shorter top ratio meant the newer 7g pluses are more efficient, if slower accelerating.

My amazing non BE estates averaged 40mpg approx since having it, but a lot of that is motorway stints and rural driving tours.

 

[Rory]

nrg220 : Interesting ... I almost bought a new Honda Jazz 1.4 CVT instead of my 3yr old C220 estate (no this is not a joke!) .... I think a Jazz would give far better mpg on urban short trip driving ... plus love the magic seats, but am glad I got the Merc estate!

We've got a Jazz, although it's a manual. I use it quite a lot and can easy get 50MPG on the trip in urban / semi rural use. I don't know how accurate the trip meter is though.

 

[NP46]

My C220 is returning 38mpg straight out of the box, already a vast improvement on my last car so i'm happy.

Nik.

 

[Winslow]

My E 220cdi has averaged 47.6 since new tootling around Somerset mainly but has done 60 on a long leisurely motorway run. About the same as a VW scirocco 2.0 DSG I drove recently and far better than a VW Jetta 1.6 TDI DSG I drove last week.