are merc cdi's known for 'bad' mpg

[Hudsonhicks]

when i say bad mpg i mean in a diesel contex.!!

i have a clk220 cdi sport 2006 and my computer never registers above 40mpg.. even on a long run.

im guessing its to do with the automatic gear box.. sometimes its "stupid" it sometimes i look down at the rpm and its blatently holding onto 4th gear when it can easily be in 5th

my previous car (audi) was far better on fuel and was a 2.0 tdi.. probs the 6 gear manual was the reason.

will remaping help? i sometimes feel i might has well gone for a v6 petrol and had extra fun!

 

[chord]

If you want good economy, then it has to be a 4 pot diesel, as you have but VAG's seem good for MPG, as do BMW's, Fords.

Others such as Honda's, Alfa's(2.4) have lot's of posts about poor mpg, talking around 7-8 less than stated figures. The auto tends to hit MPG, but this was far more noticeable in the past, these days they can match a manual.

As yours is a sport is the gearbox programmed to be more aggressive(usually means it holds it's revs longer!)

 

[moonloops]

If you are all that worried about MPG walk

 

[Deleted member 37751]

Check the ATF levels, that may be why it's holding on to gears slightly longer.
Also depends how heavy footed you are aswell, I've got a Mark 5 Golf 2.0 GT TDi that I run around in and it gets about 50 mpg on a good run, so yours may not be so bad...

 

[John]

I once had a 2001 BMW Alpina B10 V8.

Although it returned 21mpg religiously, I often discovered it too would be in 4th until it got over 50mph and then would change.

I would only know this by flipping the gear stick over to manual mode and it would report in the dash what gear it was in.

A quick flip to change up and it would change into 5th and stay there...

Probably wouldn't have done much more but still annoying.

 

[hawk20]

It's all down to how you drive. I can get 45 plus on a run with a bigger heavier car than yours but the same engine (E 220cdi estate). Others can get even more.

 

[andylinney]

I've been pleasantly surprised, my auto B180 gives me about 45 to the gallon on my 50 mile commute on every type of road (35 miles open country road, the rest city / nose to tail motorway) and if I'm gentle I can see 50mpg on a clear run with no traffic. It's night and day for me coming out of an Impreza that returned 18mpg on the same journey.

 

[newboyuk]

In first full tank of diesel in a W221 I have had 35mpg

very happy here

 

[gIzzE]

I think the main problem is most Mercs are autos and they are seriously behind with their auto 'boxes compared with the competition, Audi has DSG, BMW has DCT and the latest ZF 'boxes, which really does make a huge difference.

When BMW swapped from the older zf 'box to the latest one mpg improved by around 30% with no other changes made, you can feel it snap through the gears quickly and smoothly and you just don't get that 'rubber band' feeling that you get with Mercs.

Gearboxes make a huge difference to mpg and this is one area I feel Mercedes needs to improve upon.

 

[John]

I've been pleasantly surprised, my auto B180 gives me about 45 to the gallon on my 50 mile commute on every type of road (35 miles open country road, the rest city / nose to tail motorway) and if I'm gentle I can see 50mpg on a clear run with no traffic. It's night and day for me coming out of an Impreza that returned 18mpg on the same journey.

It's down to the individual to decide where there financial priorities lie, I totally understand that. However, wasn't it a lot more fun to be driving the Impreza over the B?

I think the main problem is most Mercs are autos and they are seriously behind with their auto 'boxes compared with the competition, Audi has DSG, BMW has DCT and the latest ZF 'boxes, which really does make a huge difference.

When BMW swapped from the older zf 'box to the latest one mpg improved by around 30% with no other changes made, you can feel it snap through the gears quickly and smoothly and you just don't get that 'rubber band' feeling that you get with Mercs.

Gearboxes make a huge difference to mpg and this is one area I feel Mercedes needs to improve upon.

They also seem to have 7 or 8 gears as well now - so I wonder if the shortest gear means really low revs cruising at 70/80mph?

PS: I seem to remember the username gIzzE and recognise that dog - were you on BM3W/MTorque once upon a time?

 

[Mcnasty]

It's all down to how you drive. I can get 45 plus on a run with a bigger heavier car than yours but the same engine (E 220cdi estate). Others can get even more.

For comparison; Even with the E320 CDi I can attain 45 mpg on longer motorway drives doing between 70 & 75mph. Doing 80mph over a long period sees the economy drop to to about 38mpg.

 

[Stratman]

I've just driven from Blackheath, through the Blackwall Tunnel, M11, round the M25 and up the M3 doing 70 where permitted, 50 through the roadworks and got 62 mpg. That's a C200 cdi 5sp auto estate.

 

[Dieselman]

I think the main problem is most Mercs are autos and they are seriously behind with their auto 'boxes compared with the competition, Audi has DSG, BMW has DCT and the latest ZF 'boxes, which really does make a huge difference.

When BMW swapped from the older zf 'box to the latest one mpg improved by around 30% with no other changes made, you can feel it snap through the gears quickly and smoothly and you just don't get that 'rubber band' feeling that you get with Mercs.

Gearboxes make a huge difference to mpg and this is one area I feel Mercedes needs to improve upon.

Mercedes gearboxes are cutting edge and work well, however the slurring you refer to is deliberately programmed in tot eh software so give the smooth delivery of torque.

Mercedes don't want their drivers to feel it snapping through the gears.

 

[kusanku]

will remaping help? i sometimes feel i might has well gone for a v6 petrol and had extra fun![/QUOTE]

You could have gone for the V6 diesel and had extra fun as well as better economy
Seriously, I get better mpg than that from my CLK 320cdi. On a run to North Wales last week, I averaged 46mpg on a mixture of motorway and A roads: I have never had less than 40mpg on run. Around town I get 27-29mpg.

I have had four cdi engines now, and only one has given poor mpg. My first was an early C220cdi, which gave around 45mpg on a run driving at strictly legal speeds: it dropped off rapidly if I put my foot down though. Next I had a 210 series 320cdi, which also gave about 45 mpg on a run at legal speeds, however it was not so good around town, giving as low as 19mpg in bad traffic. However, my next e-class, a 211 allegedly with the same straight six engine, was nowhere near as good. The best I ever got was 43 mpg, with long stretches at 50mph: typical mileage on a run was 36-39mpg, so similar to your CLK, and a long way off the manufacturers figures.

There have been quite a few posts on here about mpg figures falling short of those claimed by Mercedes. My impression is that it is more of a problem with the four-pot engines, both diesel and petrol.

 

[gIzzE]

It's down to the individual to decide where there financial priorities lie, I totally understand that. However, wasn't it a lot more fun to be driving the Impreza over the B?



They also seem to have 7 or 8 gears as well now - so I wonder if the shortest gear means really low revs cruising at 70/80mph?

PS: I seem to remember the username gIzzE and recognise that dog - were you on BM3W/MTorque once upon a time?

Yeah, that was a good forum and I was genuinely gutted went it went.

My old man just bought an F11 520d auto and that is doing 2100rpm at 85mph and returning 46mpg.
At 75mph it is at 1900rpm and giving around 50mpg.

 

[gIzzE]

Mercedes gearboxes are cutting edge and work well, however the slurring you refer to is deliberately programmed in tot eh software so give the smooth delivery of torque.

Mercedes don't want their drivers to feel it snapping through the gears.

It is just as smooth as my 7g through changes, but if you look for it you can tell it changes very quickly, that was what I meant by 'snapping through the gears' not that it was a jerky change. It feels very similar to the DSG type 'boxes and is very mpg friendly, the fact the mpg figures for the autos are the same, and even better on some models, than the manual version is testament to that.

It would be interesting to see how much of an improvement Mercedes could get by taking out that 'slurring', my guess would be they can't get enough of a difference so not worth it, otherwise they would have done it already as mpg and emissions is everything these days.

 

[blaser24nig]

If you are all that worried about MPG walk

 

[gIzzE]

You could have gone for the V6 diesel and had extra fun as well as better economy
Seriously, I get better mpg than that from my CLK 320cdi. On a run to North Wales last week, I averaged 46mpg on a mixture of motorway and A roads: I have never had less than 40mpg on run. Around town I get 27-29mpg.

I have had four cdi engines now, and only one has given poor mpg. My first was an early C220cdi, which gave around 45mpg on a run driving at strictly legal speeds: it dropped off rapidly if I put my foot down though. Next I had a 210 series 320cdi, which also gave about 45 mpg on a run at legal speeds, however it was not so good around town, giving as low as 19mpg in bad traffic. However, my next e-class, a 211 allegedly with the same straight six engine, was nowhere near as good. The best I ever got was 43 mpg, with long stretches at 50mph: typical mileage on a run was 36-39mpg, so similar to your CLK, and a long way off the manufacturers figures.

There have been quite a few posts on here about mpg figures falling short of those claimed by Mercedes. My impression is that it is more of a problem with the four-pot engines, both diesel and petrol.

There is a very little in it mpg wise between 4cyl and 6cyl cars and even less so when the car is an auto, and the heavier they get the less the difference gets, however peoples expectations are greater with a 4 cyl and they also want to drive them as quick and that is only going to have a big impact.

The figures for my E320cdi w211 V6 are...

Urban 27.70 MPG
Combined 37.20 MPG


Which is pretty much bang on.

The extra urban figure is 45.60 MPG which is impossible to get 99% of the time, however, if I follow the test guideline and drive for 6 miles with an up to temperature car averaging 39mph and reaching 70mph at least once I can see around 42mpg, if I took out all the heavy options like electric seats, spare wheel sun roof etc. etc and put on a 205 width tyre I could probably claim back the extra 4mpg and see the official figures.

I think many people think extra urban is motorway driving, it isn't.

If you look at the urban and combined figures for a given car that is pretty much what most people will get, forget extra urban unless you live in an area where there is no other traffic and you don't go over 40mph.

 

[ucr]

Get a chip for it - You will get about 30BHP more ! and more MPG (I can get 55MGP from a B200CDI)

 

[John]

M3Torque took over from MTorque when Matt left. Few of the old regulars on there if you didn't know...

I think many people think extra urban is motorway driving, it isn't.

I used to think this many moons ago but I found out it was the bizarre recipe you mention.

However, given motorway would be a more useful figure to know - it should really be motorway driving i.e. running at a consistent 70mph and 80mph or similar for a certain number of miles.