Poor mpg for c270 diesel?

[tony2311]

Might be a silly question (and it is not intended as a dig at lady drivers) but is she nudging the gearstick and runing in a lower gear rather than D?

Trust me thats not a silly question, the reason why i had a second hand engine/gearbox fitted its becuase she drove the car on motorway why it was in failsafe mode(second gear?) and blown a hole on the engine wall


Still getting lots of different figures from average 35 to 45. i am driving like a girl at the moment and engine never rev pass 2300 but the reading still average 36mpg after 200miles @ 30mph average, i live in sheffield and traffic jam is not a problem, but most journey is 1 mile though town then M1 jnt 33 to 30 thats 11miles ish then another 1.5 miles though town. twice a day (school run) and me commute to work 1.5miles though town(no traffic just 2 roundabout) some members on here qoute better figures for their petrol !

 

[maggragg]

Hello

I have the same problem with my car that I bought two weeks ago, 2003 model E270 CDI. The Mpg is too much I think. The car has 80.000 Miles on it and for the last 1100 miles it has 34 MPG and I drive really carefully and 95 % is on the highway at 56 MPH, or 90 kmph as I´m used to that as I live in Iceland.

I was changin oil, fuel filter, air filter and the tyre pressure is as is statet in the manual.

Am I right that it is way too much MPG for this car, at least as I drive as econominly as I can.

What can the problem be, something with the injectors? I have boght some special oil treatment for Common rail engines and will se if it will help.

I was hoping for MPG like 40 - 50 for the driving that I´m dooing as I live in a town with less than 1000 in populations and there are 60 miles to Reykjavik as I drive most too.

Thanks

 

[NJones59]

Hello

for the last 1100 miles it has 34 MPG and I drive really carefully

Another silly question from me... but you never know

Are you looking at the figure since last reset rather than the actual mpg on the next page of the dashboard computer?

 

[maggragg]

Another silly question from me... but you never know

Are you looking at the figure since last reset rather than the actual mpg on the next page of the dashboard computer?

Yes, I´m looking at the since last reset and not the after start page. After start screen can get little lower if I just drive out of town and on high way but I think that max I have got after 100 miles with tailwind and constant 90 kmph is up to 40 MPG or exactly 6,9 liters per km. that is the lowest figure I have ever seen.

 

[sr-performancelive..]

Hi,
I know it's not quite relevant but I have recently remapped a ML270 for a customers wife. It was returning 30mpg on the daily commute/shopping ect, but is now returning 35mpg. and this on a vehicle that weigh's quite a bit more than a C270.
Just a tip but try and use shell optimax or equivalent as they are better than supermarket fuel and do make a difference, and once a month put a bottle of forte in tank, prob best injection cleaner i've used...

 

[jberks]

Not sure about the optimax - I've never found any difference in mpg. Good for detergents though, but the Forte is doing the same job.
Mine, on my 45mile 60-80mph (+ a bit of town driving) commute will return 41ish. The best I've seen is 48 and my old 8 mile traffic commute, around 26.
What I have also noticed is that the computer's results are questionable. I drive 6 miles from home and by the time I reach the M1, its reading 31mpg. 30 miles of motorway later its 38mpg. Then slowing down for the roadworks, I make a point of not braking but dropping the throttle and coasting it down. By the time I reach the roadworks with this method, it's nudging 40mpg. So 38->40mpg average simply by coasting for less than a mile. Doubtful.

 

[survey]

Mines starting to loosen up, and I'm getting around 35mpg, on short runs and town stuff ............ and around the 45 mpg mark, on long runs .............. if I stick to around 75-80 mph on the motorway, a can get upto 55mpg, on a good day !

My 220cdi estate (latest model) now has just over 12K on it. Around town and shortish runs of up to say 20 miles I am getting 39-40mpg. Longer runs I can get 42-43mpg. Also Climate Control is kept on Auto. This consumption is measured tank/tank and over the life of the car rather than using the on-board computers that on my car are constantly between 5-8% optimistic. Those members only reading the computer may be being fooled - mine has shown over 60mpg on the 'From Start' computer at times! Looks good but is fairly meaningless other than the fact that it encourages one to keep driving economically!

I use both 'C' and 'S' mode and cannot detect any difference in consumption - is one mode likey to be more economic than the other? My car seems to like getting up to speed quickly for best consumption. Certainly town and slow driving drag the consumption down rapidly!

I am hoping that as the engine loosens up that my figures will improve. On previous diesels this has taken up to 40K miles!!

 

[grober]

I would check that your engine thermostat--cooling fan/s are working to spec after the rebuild . Diesels are inherently slow to warm up but running with a cold engine will markedly increase fuel consumption. Remember also using the aircon will chop off a few mpg's

 

[NJones59]

You stated that the average for the last 1100 miles is 34 mpg. Are these miles all driven by you or did the previous owner have some 'fun' before he sold it to you bringing the average down? Now that the car is in your hands it may be worth resetting the from start trip and checking it over a few weeks. I might be clutching at straws on your behalf but mine recently returned around 53mpg over a 200 + mile run (albeit mainly motorway (if you can call the M25 a motorway) and the from start average reads 46 mpg over the last 4500 miles (and I don't drive in slippers )

 

[maggragg]

You stated that the average for the last 1100 miles is 34 mpg. Are these miles all driven by you or did the previous owner have some 'fun' before he sold it to you bringing the average down? Now that the car is in your hands it may be worth resetting the from start trip and checking it over a few weeks. I might be clutching at straws on your behalf but mine recently returned around 53mpg over a 200 + mile run (albeit mainly motorway (if you can call the M25 a motorway) and the from start average reads 46 mpg over the last 4500 miles (and I don't drive in slippers )

When I bought it I reset the computer so I have drived 1100 miles myself. I have drived very carefully with few exeptions as I had to try the car.

I have also calculated the MPG with brim to brim for method and it shows 34.9 for the last 1000 miles so it actualy is slightly better than the computer says, almost the same.

I have 245/45R17 tires with 29 pounds in the front and 30 in the rear.

The thermomete for the cooling water is always one notch under the 80 mark

I have bought wynn's high pressure 3 and will put it in the tank when it will have around 50 liters in it.

 

[Alex M Grieve]

Not sure about the optimax - I've never found any difference in mpg. Good for detergents though, but the Forte is doing the same job.
Mine, on my 45mile 60-80mph (+ a bit of town driving) commute will return 41ish. The best I've seen is 48 and my old 8 mile traffic commute, around 26.
What I have also noticed is that the computer's results are questionable. I drive 6 miles from home and by the time I reach the M1, its reading 31mpg. 30 miles of motorway later its 38mpg. Then slowing down for the roadworks, I make a point of not braking but dropping the throttle and coasting it down. By the time I reach the roadworks with this method, it's nudging 40mpg. So 38->40mpg average simply by coasting for less than a mile. Doubtful.

I think your numbers may be correct, or correct in proportion to any variation between the computer and a "brim to brim" calculation.


I get a similar effect driving to South London from Warwickshire:

1. start of the journey (cold engine, some stopping and starting) and the average consumption for the day begins around 25-28 depending on the weather and improves to 33-35 by the time I reach the M40 (15 miles)
2. then the motorway phase at around 2,000 rpm, or just over sees me get to 40 mpg within half an hour and on perhaps to 42 by the time I reach the M25
3. the M25 variable speed limit then slows me to around 60 mph and it is surprising how quickly the days average can go to 45 (warm engine, less speed) and it does seem to bias the days average disproportionately.

Same pattern as yours, I think.

I agree with your skepticism about "premium fuels". I tried super unleaded (or whatever they call the 97 RON petrol) for a trip around France in the 129 this year. Made no difference at all.

 

[sr-performancelive..]

I fully understand your sceptism about the different fuels but they do usually make a difference, the prob with modern ecu's are they learn the values of the regular fuel you use and adapt to them, so when you do change the main reason you dont feel the benefit is the ecu not relearning.
The best way for the ecu to relearn and adapt to new values is to disconnect the battery for a short while so it has to start afresh again... not 100% guaranteed though...

 

[Alex M Grieve]

I fully understand your sceptism about the different fuels but they do usually make a difference, the prob with modern ecu's are they learn the values of the regular fuel you use and adapt to them, so when you do change the main reason you don't feel the benefit is the ecu not relearning.
The best way for the ecu to relearn and adapt to new values is to disconnect the battery for a short while so it has to start afresh again... not 100% guaranteed though...

Understood Steve, and of course there should be a difference - the premium fuel has a higher energy content, so it should either let you go faster (difficult to tell subjectively) or enable better mileage if all else is equal.

Perhaps your point is the reason that those of us who have tried (even over several refuels) and found no difference have become skeptical.

 

[sr-performancelive..]

Yep, about right that Alex.
But the better fuel does work better with a remap as the values are altered at the same time...

 

[S.Speed]

Trust me thats not a silly question, the reason why i had a second hand engine/gearbox fitted its becuase she drove the car on motorway why it was in failsafe mode(second gear?) and blown a hole on the engine wall


Still getting lots of different figures from average 35 to 45. i am driving like a girl at the moment and engine never rev pass 2300 but the reading still average 36mpg after 200miles @ 30mph average, i live in sheffield and traffic jam is not a problem, but most journey is 1 mile though town then M1 jnt 33 to 30 thats 11miles ish then another 1.5 miles though town. twice a day (school run) and me commute to work 1.5miles though town(no traffic just 2 roundabout) some members on here qoute better figures for their petrol !

Hi Tony... I think I know your car and have seen it whilst it was being repaired..
Did you have it repaired in Kirkham?
If so then we are "neighbours".

 

[jibcl500]

My 220cdi estate (latest model) now has just over 12K on it. Around town and shortish runs of up to say 20 miles I am getting 39-40mpg. Longer runs I can get 42-43mpg. Also Climate Control is kept on Auto. This consumption is measured tank/tank and over the life of the car rather than using the on-board computers that on my car are constantly between 5-8% optimistic. Those members only reading the computer may be being fooled - mine has shown over 60mpg on the 'From Start' computer at times! Looks good but is fairly meaningless other than the fact that it encourages one to keep driving economically!

I use both 'C' and 'S' mode and cannot detect any difference in consumption - is one mode likey to be more economic than the other? My car seems to like getting up to speed quickly for best consumption. Certainly town and slow driving drag the consumption down rapidly!

I am hoping that as the engine loosens up that my figures will improve. On previous diesels this has taken up to 40K miles!!

Got 54mpg from our 220cdi recently!!!!!

jbi

 

[st4]

Had 53.5mpg from my car. Warm weather and millers SP4 does nicely.

 

[psmart]

Your car is either problematic (MAF, Injectors, coked up) or your wife's style of driving is counter-economy. Driving economically is not driving like a grandad, its reading the road, what point is there to flooring a car, only to brake 2 seconds later, you floor it when there is fun to be had!!

Injectors, if they havent been changed and havent covered a great distance wont need re-calibrating in the ECU. The MAF certainly causes higher fuel consumption and reduced power, a coked up exhaust creates more back-pressure etc.

In both the C220 and the ML500, the computer is pretty accurate (as proved with garage receipts in an earlier post). 25++ in an ML500 means you being lighter and more aerodynamic with an efficient diesel should be 40+.

The C220 can get 66mpg, but currently, commuting to work and the driving long distances flat out (137mph), over 2300miles, its 34.2mpg.

The ML270 I could easily get 28-30mpg without driving like grandad, lowest Ive ever had, harsh driving and flat out was 22mpg.

The Prius, when I first got it obtained 67mpg, but recently its been averaging ~55mpg on the same routes where the C220 averaged high forties. The Prius is petrol and automatic, the C220 is diesel and manual (sequentronic), 200Kg in weight between them, similar sized cars.

So cutting it short, get you car checked, it sounds well out of kinter.

 

[psmart]

Your car is either problematic (MAF, Injectors, coked up) or your wife's style of driving is counter-economy. Driving economically is not driving like a grandad, its reading the road, what point is there to flooring a car, only to brake 2 seconds later, you floor it when there is fun to be had!!

Injectors, if they havent been changed and havent covered a great distance wont need re-calibrating in the ECU. The MAF certainly causes higher fuel consumption and reduced power, a coked up exhaust creates more back-pressure etc.

In both the C220 and the ML500, the computer is pretty accurate (as proved with garage receipts in an earlier post). 25++ in an ML500 means you being lighter and more aerodynamic with an efficient diesel should be 40+.

The C220 can get 66mpg, but currently, commuting to work and the driving long distances flat out (137mph), over 2300miles, its 34.2mpg.

The ML270 I could easily get 28-30mpg without driving like grandad, lowest Ive ever had, harsh driving and flat out was 22mpg.

The Prius, when I first got it obtained 67mpg, but recently its been averaging ~55mpg on the same routes where the C220 averaged high forties. The Prius is petrol and automatic, the C220 is diesel and manual (sequentronic), 200Kg in weight between them, similar sized cars.

So cutting it short, get you car checked, it sounds well out of kinter.

ps) Just to add, is your air filter ok (look at the airfilter, left side of engine, a guage is on it, if any of it is red or all red, then get it changed). Also the Intercooler I found can get crap in it, which reduces air charge cooling, and thus efficiency/economy).

 

[maggragg]

psmart, thats interesting. If there is a problem with the MAF, is that something that you will find out if you connect the car to a computer. Don't want to spend for new MAF if it dosen't do anything...

I have new air filter in mine so it will be the MAF, Injectors (hope not as it is really expensive), intercooler or choked up exhaust ( How do I find out?)

It should show me better MPG than 35 to 41 as 41 as max for long range, highway driving on 56 - 60 mph all the time.