c200cdi auto - MPG ?

[IceBoy]

Hi All,

Only had the C200cdi auto estate for a few days but have done a few trips.

The car is a 2006 "55"
104k - full MB history
Auto
Estate

These are my findings:

40 miles shopping trip, 30 miles of motorway driving at 70mph
10 miles around the town and in car parks etc

Trip computer shows 31mpg

140 mile motorway cruise at 70mph

Trip computer showed 39mpg

Now I have only done 190 miles and it seems my tank only has half left!!!

At this rate I will have ran out before even 400 miles.....on one tank and this is driving like miss daisy.

Is this normal?

Please help
IceBoy

 

[st4]

Does sound a tad low, but not drastically so

 

[Stratman]

I have the estate version of the C200 cdi,(04 reg) with a similar mileage. The 'since last reset' shows 27000 miles at an average of 49.5 mpg. What does yours show?

Yours does sound a bit low, especially the motorway mileage. On a 200 mile M'way trip at 70mph I would expect over 50mpg.

 

[JOB-BLACK-RAT]

Never been good with MPG, I do it the tank.

MY '03 C220d saloon with same sort of driving as yourself does 560 miles to the tank (last fill up yesterday from reserve was £75).

 

[IceBoy]

I will wait and see what I get to the tank but at this moment looks like 400 miles is going to very difficult even with mainly motorway cruising.

If it does not get better, what is the best bet? Go to a MB independent? How do I know if the MAF is OK?

What else.....this is our main car and I was expecting 40mpg average at least.

IceBoy

 

[Oli]

That does seem a bit low for a 200 CDI, my CLK used to manage 35 on the motorway.

 

[kwakdonut]

The cold weather very definitely affects MB diesels - I have seen my MPG drop from 45 to 42 on the motorway and from 42 to 38 round town.

Is the engine getting up to correct temperature? Should be 80-85c on the guage.

Does your car have heated seats/engine heater etc? The heavier load on the electrical system will affect fuel economy too

 

[crockers]

I'm currently getting around 32 - 35 on short journeys in this weather..

 

[IceBoy]

The story gets worse!

I've been to Kent and back a 200 mile return journey.

I drove at 70 mph all the way, the motorways were clear and the local driving was no more than 15 miles.

So basically this tank has been 85% motorway and 15% town driving.

The tank has given me 390miles !!!

Yikes !!!

My brothers x5 diesel is much better....there has to be something wrong......?!?!?!?!?

Please help, I'm a new owner and need to know what to check and where to check?

Thanks in Advance
IceBoy

 

[Stratman]

What temperature is the engine running at? Thermostat failures are not at all uncommon and can hit fuel economy. It should be up around 80C-90C.

Other things to check are the air filter, the MAF as has been already mentioned, and leaky fuel pipes around the injectors.

 

[IceBoy]

Thanks, and I will check these....not sure where the MAF is located though, there is a huge plastic MB cover on the engine.

The temperature gets to just below 80, where 80 is the middle point.

IceBoy

 

[renault12ts]

The cold weather very definitely affects MB diesels - I have seen my MPG drop from 45 to 42 on the motorway and from 42 to 38 round town.

Is the engine getting up to correct temperature? Should be 80-85c on the guage.

Does your car have heated seats/engine heater etc? The heavier load on the electrical system will affect fuel economy too

And yet, I recorded my highest ever indicated MPG at 51.7, in sub zero temps, in early December. The weather forced an average of about 50MPH.

 

[kwakdonut]

And yet, I recorded my highest ever indicated MPG at 51.7, in sub zero temps, in early December. The weather forced an average of about 50MPH.

So there's your answer to good mpg then - drive everywhere @ 50mph!!

 

[rf065]

And yet, I recorded my highest ever indicated MPG at 51.7, in sub zero temps, in early December. The weather forced an average of about 50MPH.

My best yet was today, temp about 0C, sorry about the picture, taken one handed on my mobile phone, it does read as 65.1mpg though and 58mph.

http://i258.photobucket.com/albums/hh242/rf065/Photo0122.jpg


Russ

 

[gIzzE]

The story gets worse!

I've been to Kent and back a 200 mile return journey.

I drove at 70 mph all the way, the motorways were clear and the local driving was no more than 15 miles.

So basically this tank has been 85% motorway and 15% town driving.

The tank has given me 390miles !!!

Yikes !!!

My brothers x5 diesel is much better....there has to be something wrong......?!?!?!?!?

Please help, I'm a new owner and need to know what to check and where to check?

Thanks in Advance
IceBoy

Hold on.

Have you reset the OBC??

Have you reset the odometer when you fill up and then worked out what the real MPG is??

I think the C200 has a 62 litre fuel tank, and it will have around 6 litres reserve, so you should use 56 litres (12 gallons) between fill ups, so around £70 to fill up with todays prices (average of about £1.25 a litre).
Does that sound about right??

If so, you have done 390 miles? so that is 32.5 mpg.
In the cold with stop start driving that sounds slightly low to me, I would expect around 34-36mpg from a tankful.
However, if the reserve is 8 litres as many are, and maybe you didn't reset the odo exactly when you filled up that could be another 2 mpg.

As someone else suggested, get on a long stretch and reset the MPG counter while sat at 70mph and see what you get over 3 miles without breaking.

 

[gIzzE]

Also, what are you comparing on the X5?? MPG or range?

The X5 has a 93 litre tank, so at 32.5mpg it will do 635 miles before hitting the reserve, most I would guess only see around 450 miles though, which is under 23mpg.

 

[st4]

Also, what are you comparing on the X5?? MPG or range?

The X5 has a 93 litre tank, so at 32.5mpg it will do 635 miles before hitting the reserve, most I would guess only see around 450 miles though, which is under 23mpg.

23mpg, from an X5, I would say lucky

 

[gIzzE]

Haha, an average tank on a 3.0d will do 23mpg, I know so many people who have owned them and that seems to be the general figure.

 

[IceBoy]

I think you are right that over a tank I have got about 32-33mpg.

This was however 85% motorway trips sat at 70mph. Will little traffic.

So may this is about right from a 200cdi auto ? Over the same sort of journeys the X5 can do the same. The comparision was for simialar trips. I've had the X5 for weeks at a time and can say that 32mpg is fairly easy with 85% motorway trips.

IceBoy

 

[timskemp]

Some quick questions:

1. What are your tyre pressures? If they are on the low side then you'll be suffering
2. What mode is the gearbox in?
3. Have you got a roof box on?
4. Does it smoke when you put your foot down?
5. Is it getting into the right gear - how many RPM cruising at 70mph?
6. What revs is it changing up at, driven gently it should change up between 1500 and 2000 rpm, driven hard in S mode it should change up at or near the redline.
7. Do you start then pull off straight away or are you idling to warm up the interior / defrost?

At 104k miles if it has never had the MAF replaced (air mass meter / mass air flow sensor) then it will probably need one, get an independent to test it, or take a punt and just replace it anyway. Also replace the air filter at the same time. If the MAF is failing then it will run a default fuelling map and can be thirsty

I'm averageing about 34mpg from a hard-driven E270, bigger car, bigger engine. I expect to see 38-40 mpg on the motorway at 70-80, 25-30 in town in summer and 20-25 in town in winter.