C180k - TERRIBLE mpg - Please help

Page may contain affiliate links. Please see terms for details.

October

New Member
Joined
Dec 1, 2010
Messages
15
Hi Folks,

Please take a moment to help me - I'm at the end of my tether.


I have a 2004 W203 271 engine C180 Auto. ~60,000 mile on the clock.
I bought it about 17 months ago.

Problem: The fuel consumption is awful. Always has been. Around town I'm getting about 20mpg avg. 28mpg on the motorway, if I'm lucky.
I'm getting about 230 miles from a tank.

The EML is on and has been for some time. I took it to a garage ages ago, it was complaining about the O2 sensor, I got it replaced. The fuel consumption didn't improve and the engine light came on a few weeks/months afterwards.

Some questions:
1) What can I do to get decent mpg?
2)What mpg should I expect from a car of this age?
3) Is the O2 sensor the problem? Is it simply inputting too much petrol to the engine?
4)What part does the MAF play in this?
Could replace it solve the problem?

I'm hoping it's not oil in the wiring loom. I simply don't have the money to fix it (due to buying a house since buying the car - it's eating all my money!).
If it is oiling the wiring loom, I'm going to have to trade it in and if so, I'm not going back to Mercedes again. I had a manual C200 CDI before this one and had nothing but bother from the DPF. I traded it in to buy this C180. Petrol meaning having no DPF.

All help very much appreciated. Thanks!

Steve,
Northern Ireland.
 
Oil in wiring loom is easy to check (though I don't think that's the problem), disconnect the connector - with the engine switched off - and look for oil. There's also a prevention measure - will post a link.

20-22mpg in town is what I get, however not sure what you refer to as 'in town', I am referring to central London traffic crawl, which is real bad.

Normal Motorway driving at 70-80mph will see 30-36mpg.

Best consumption figures I had from this car was when averaging 55mph on an A road driving very moderately: 40-46mpg.

That's computer figures, not real-life 'brim-to-brim'.

As for the EML light.. regardless of what happened ages ago, you need to get the codes read now, and take it from there. It's a better way to deal with this than to take gueses at O2 sensors and MAFs, I think.
 
Oil in wiring loom is easy to check (though I don't think that's the problem), disconnect the connector - with the engine switched off - and look for oil. There's also a prevention measure - will post a link.

20-22mpg in town is what I get, however not sure what you refer to as 'in town', I am referring to central London traffic crawl, which is real bad.

Normal Motorway driving at 70-80mph will see 30-36mpg.

Best consumption figures I had from this car was when averaging 55mph on an A road driving very moderately: 40-46mpg.

That's computer figures, not real-life 'brim-to-brim'.

As for the EML light.. regardless of what happened ages ago, you need to get the codes read now, and take it from there. It's a better way to deal with this than to take gueses at O2 sensors and MAFs, I think.

+1
We used to get around 22mpg in town in a C200 Komp. I wouldn't worry about your fuel consumption, it sounds about right. My dad recently got the o2 sensor replaced in his 280 CDI and did not improve the fuel economy, but it needed changing anyway.

Its worth to maybe have a look at the MAF sensor for any dirt grease etc... on it but as markjay said, connect it to a code reader and if you can, get them read by a approved mercedes specialist.
 
I have a 54 plate C180 k with 81k miles and average around 34 in the winter & 36 in the summer. In really heavy London driving I have seen as low as 26 but this is exceptional. My normal driving is 1/3 city and 2/3 motorway with cruise control set at the legal limit.
 
my clk 200k strugles to get above 20mpg around town when driven normaly and is usually down to about 17mpg with my heavy right foot . on the motorway I can get about 35mpg
 
My c200k was a bag of crap for mpg aswell... Used to get 350 miles from a tank if I was lucky.. Mainly motorway miles at 60-70 aswell!
 

Users who are viewing this thread

Back
Top Bottom