Poor mpg for c270 diesel?

[tony2311]

got a 02 c270cdi. had a secondhand engine in recently, i am averaging 30mpg at average speed of 29mph. my journey is mainly 24miles of motorway/aroad twice a day (school run) and i drive to work 2 miles most days small roads but no jams. i get 50mpg on the same journeys on a scenic.
i know c class are heavry and its auto but 30mph average doesnt look good. is this about right or is there something wrong with my car?
i see others on here get regular mid 40s so it looks a big difference

 

[Blobcat]

Difficult one really, my E320CDI averages ~36.6mpg for 60K miles average our Caravelle is averaging ~26mpg for 20K miles. The Caravelle does the school run and tends to get the short journeys, I have a 13.4 mile each way commute were I only see high 20's on the E's trip computer however I also do lots of long journeys where it shows 42mpg.

 

[discoking]

got a 02 c270cdi. had a secondhand engine in recently, i am averaging 30mpg at average speed of 29mph. my journey is mainly 24miles of motorway/aroad twice a day (school run) and i drive to work 2 miles most days small roads but no jams. i get 50mpg on the same journeys on a scenic.
i know c class are heavry and its auto but 30mph average doesnt look good. is this about right or is there something wrong with my car?
i see others on here get regular mid 40s so it looks a big difference

Sounds about right imo and most people I know with these types of big diesels get roughly the same or less as most is just round the doors journeys.

 

[Rappey69]

would say that is about right for average. I average 30-25mpg. Its short journeys that destroy a good average figure.

 

[NJones59]

That sounds terrible. My commute sounds similar to yours 24 miles motorway and A (and a B road!) and I regularly get 41 mpg on that run. I recently reset the computer following a service and it was showing an average of 46.7 mpg over 14000 miles and this week I did a 600 mile, mainly motorway trip, and returned an indicated 52 mpg.

 

[britnordic]

I agree with Nigel and mine's an estate, if your journey is NOT stop start then I would expect nearer the 40mpg. Often see over 50mpg on the computer, but that's not completely accurate!

Tony

 

[S.Speed]

Hi..
My commute to work is 10 miles of mainly rush hour traffic and I typically get32 - 35mpg..
HOWEVER on a run I easily can achieve 45mpg and have several times managed over 50mpg..
About 3 months ago I did a trip to Southampton and back (Over 600 miles total).. It was mainly motorway with about 40 miles of A roads and 10 miles city driving.. My trip computer reckoned 51.3mpg..
My tank was still a quarter full when I got back home..
I Brimmed my tank at the same pump I used at the start of the journey and used a calculator to work out the mileage.. After all the trip computer couldn't possibly be correct... Could It ?
It worked out at 51.9mpg..
In the 4 months or so that I have owned this car I am constantly impressed with how good it is on fuel..
Tony.. I would try some of the injector cleaner fuel additive..
I have used Millers Dieselclean in the past but I tend to find with that product that the increase in MPG comes after you have had a few tankfulls through and have stopped using it..Strange I know but I have noticed this on several diesels I have used this product on.

 

[st4]

Using Millers SP4 and noting the same commute that costed £31-32pw fuel is now less than £27-28pw. Thats fairly significant over the course of a year and the car IS quieter and feels more eagre throughout the rev range from peak torque to peak power.

 

[whitenemesis]

30mile commute and I regularly got 48-50mpg

Around town 40-45mpg but on the shortest journeys the worst I see is 36mpg..

How recent was your second hand engine and was it a recon? Could still be tight from rebuild?

 

[ALFIEBEARD]

I have an E270 CDI and I do a similar journey each day to you and it always averages at least 39mpg on each tankfull, and I drive it fairly hard, I reckon the injectors need either cleaned or calibrated.

this advice is only worth what you paid for it though.

Alfie B

 

[Chrishazle]

I have a 2001 C270CDI estate (since early October last year) and show over 40mpg for 1800 miles of mixed motoring - only have to tank up every 500+ miles. I reckon something's not right - either with the car or with someone's right foot!!

 

[tony2311]

I have a 2001 C270CDI estate (since early October last year) and show over 40mpg for 1800 miles of mixed motoring - only have to tank up every 500+ miles. I reckon something's not right - either with the car or with someone's right foot!!

My mrs drive the car mainly and she is not a fast driver. Just had my injectors clean and reseal as 2 was blowing slightly. The engine was second hand, seller said it was 40,000miles but cant prove it. i just put some forte diesel treatment 2 tank full ago and 2 stroke oil in the last tank, have some redex (£10ish for 4 in costco) waiting for next tank along with some 2 stroke oil. i dont drive it fast either and cant think why it is using so much fuel
The car runs fine, lots of power(new turbo) is there a maf on this car? can the car be out of tuned?
many thanks for all the answers

 

[NJones59]

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?

 

[tony2311]

just fill the tank up today along with some redex , 21miles of motorway, a roads and little bit of town. average 37mpg but i was careful and not rev over 2300. will report how many miles to a tank when i am done

 

[Seeker_UK]

In my C270CDI, I averaged about 33/4 - diesels are not as frugal as you think.

 

[Alex M Grieve]

In my C270CDI, I averaged about 33/4 - diesels are not as frugal as you think.

I know the type of use, manner of driving and a number of other factors all make a difference, but I have had an E Class 320 CDI (2003-2006) and a 2004 S Class diesel since then.

For the E Class, the fuel consumption averaged around 40 mpg overall (43,000 miles), and now that I am retired the S has given an average (brim to brim) of 39 mpg over 22,000.

Speaking to our company chauffeur, who used an E 220 CDI (2004), cruising @ 85mph indicated, home to Heathrow, he averaged 44 mpg, I averaged 43.

I don't ever recall getting the average down below 35 for a tank of fuel on either car.

I accept that commuting in slow traffic would be bound to reduce these numbers, but I still think the diesel is a thrifty choice, I shudder to think what the "worst case" would be for petrol equivalents.

 

[whitenemesis]

In my C270CDI, I averaged about 33/4 - diesels are not as frugal as you think.

All depends on how and where you drive them..

My 10ml commute gives a respectable 40mpg Longer journeys sees an easy 45-50pg Morway runs will give over 60mpg. Always keeping up with traffic flow and close to the speed limits

And NO, I don't drive in carpet slippers!

 

[Seeker_UK]

It's interesting.

Weekly I drive about 120 miles.

Each day is usually as follows

Morning
2 miles @ 30 mph no stopping
5 miles @ 70 mph, 2 roundabouts, no stops
2 miles @ 30 mph no stops

Evening
as above but in reverse.

Every 3/4 weeks add in a longer journey of about 150 miles.


Since I've been doing this, I've owned 6 cars. These are the averages / best I got.

Saab 9000 Manual (2.3l turbo petrol) - 25 mpg / 35 mpg
C 270CDI Avantgarde SE Auto Saloon - 35 mpg / 45 mpg (just checked the figures)
BMW 330CD Auto - 33 mpg / 42 mpg
CLK 270CDI Auto - 33.5 mpg / 44 mpg
Volvo V70 D5 Manual - 37 mpg / 52 mpg
CLK320 Avantgarde Cab - 24 mpg / 29.5 mpg ()

Now, whilst I do not cane them, I don't 'drive Miss Daisy' either. Quite how people on here get better averages is quite beyond me.

On the other hand, Mrs Seeker has a 2.5l auto Ford Cougar which has a reputation for drinking for England, and she can get 30 mpg average out of it with a best of about 36!

 

[*Thumper]

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 !

 

[tikw2124]

got a 02 c270cdi. had a secondhand engine in recently, i am averaging 30mpg at average speed of 29mph. my journey is mainly 24miles of motorway/aroad twice a day (school run) and i drive to work 2 miles most days small roads but no jams. i get 50mpg on the same journeys on a scenic.
i know c class are heavry and its auto but 30mph average doesnt look good. is this about right or is there something wrong with my car?
i see others on here get regular mid 40s so it looks a big difference

Hi Tony, don't think that is very good. My 02 270 CDi is currently showing 51mpg since reset (approx 5k ago). My commute is 75 mls round trip and only 20 of these are dual carriageway rest B roads. Even if i gun it a little, very rarely falls below 47 mpg. weekend journeys consist of quite a few short ones. Also, current mileage is 177k mls.