C180K With poor fuel economy

[Faz4853]

My 2004 C180K is on managing 23 MPG doing mostly urban driving surely this is too low and something is wrong. The car is under warranty from Mercedes but they say nothing is wrong I disagree. Are there any other C180k owners out there and what fuel economy do you experiance?

 

[simon_wall69]

Have you tried super unleaded? That's what a lot of people on here do, I believe, with improved fuel economy.

 

[Micman]

My 2004 C180K is on managing 23 MPG doing mostly urban driving surely this is too low and something is wrong. The car is under warranty from Mercedes but they say nothing is wrong I disagree. Are there any other C180k owners out there and what fuel economy do you experiance?

Hi there,

Just as a secondary point, I would be interested to know what mileage your car has done - I noticed my mpg didn't seem to improve and settle down until the car reached approx 25k miles.

I used to drive a very short 6 mile trip into the town centre for work in constant stop start rush hour traffic and used to achieve only 22 - 26mpg most days. That journey could take me 30 minutes plus!!

Now, however I drive 14 miles to work each way. It takes me 25 mins on A and B roads and I see mpg's between 30 - 36 most days.

When I go on longer decent runs (for example I did 200 miles to Devon recently) then it's quite possible to easily reach 40 and upwards if I'm driving smoothly.

By the way, I only use the normal unleaded - I don't bother with any of that pricey super unleaded stuff. I tend to use BP, Shell and Texaco fuel as my local garages - I try to avoid the supermarket fuel as much as possible.

 

[turbopete]

id say your fuel consumption was about right. my E300 turbodiesel only does about 23 mpg in town!

 

[type49]

My 2004 C180K is on managing 23 MPG doing mostly urban driving surely this is too low and something is wrong. The car is under warranty from Mercedes but they say nothing is wrong I disagree. Are there any other C180k owners out there and what fuel economy do you experiance?

First of all, checking the cars data, it suggests 23.9 MPG & these are under strict conditions, so to be .9 off is pretty good. Use your computor to check the average speed in the "since reset" function. I drive in quite a lot of traffic & only average 22 MPH. If your speed is below this, then you must be in very heavy traffic a lot & should only look at the "urban" figures for a comparison. A diesel in traffic is much better than a petrol, less so on the motorway.

 

[ernieh]

C Class Kompressors MPG

Hi there,

Just as a secondary point, I would be interested to know what mileage your car has done - I noticed my mpg didn't seem to improve and settle down until the car reached approx 25k miles.

I used to drive a very short 6 mile trip into the town centre for work in constant stop start rush hour traffic and used to achieve only 22 - 26mpg most days. That journey could take me 30 minutes plus!!

Now, however I drive 14 miles to work each way. It takes me 25 mins on A and B roads and I see mpg's between 30 - 36 most days.

When I go on longer decent runs (for example I did 200 miles to Devon recently) then it's quite possible to easily reach 40 and upwards if I'm driving smoothly.

By the way, I only use the normal unleaded - I don't bother with any of that pricey super unleaded stuff. I tend to use BP, Shell and Texaco fuel as my local garages - I try to avoid the supermarket fuel as much as possible.

Although my last car was a C200 Facelift Auto, my experience almost mirrors exactly the above. For example, just before it went, I got an average of 44.2MPG over 64 miles at an average speed of 51MPH (mileage 58k). However, in town work, I could quite easly see the low 20s and even the teens particularly during winter. In fact my C220CDI isn't that much better at the moment, although with only 6k miles on the clock, I'm hoping for some improvement!

Incidentally, a former colleague with a late prefacelift manual C180 tells me that he can readily see the high 40s on a run and high 20s in town. However, I wouldn't have a manual Merc for love nor money!


Ernie

 

[Faz4853]

Thanks for the replies sounds like its not far off after all

 

[TazCBR1100XX]

Hmmm - looks like mine!

I picked up on this because I came across this thread when I was checking for answers for a similar problem on my 2004 C180K.

Up until recently, I've been getting on average 35+mpg. However, I got a P0170 DTC with a nice little yellow lamp to tell me summat was up. I rang MB and they told me P0170 was probably MAF. So I bought a new genuine Siemens VDO MAF, reset the lamp, and off I went. However, the mpg since I started getting this problem has dropped significantly, and I'm lucky to get 30mpg now on a trip to town, whereas in the past I easily got 35-36mpg on the same run.

I'm now wondering if the MAF was the actual problem, or maybe it was just a part of the problem.

I was thinking about changing out the O2 sensor, but it's expensive - and there's two of the buggers :roll: One is Upstream Catalytic Converter, and the other is Downstream Catalytic converter. Exactly which one may be most likely to be faulty is a mystery to me though - it may even be that none of them are faulty.

Time to buy a better scanner tool I think and see if I can get to the bottom of it. In the meantime, does anyone have a better clue as to where the problem may be? I'd rather not spend hundreds chasing a ghost :Oops:

And finally, if I do buy a better scanner tool, has anyone tried the Auto Enginuity kit, and if so, is it any good?