C250td poor fuel economy

[darkchild101]

It appears fellow owners of this beast (w202 model) are seeing about 35mpg. When I put £20 I am getting about 100 miles out of 15 litres so roughly about 28mpg. I have tried to alter my driving style and be more gentle with my right foot yet I have not seen any real improvement.

What could cause such poor fuel consumption or economy

 

[a111r]

Mine did around that on the school run. But 37 /38 mpg on a proper run. Not great!
It's the price you pay for outdated, yet bullet proof, M.B. oil burners.

As to faults; semi-blocked induction or exhaust. You could de-cat and egr-delete easily.
More likely is poor injector spray patterns - but Bosch nozzles are cheap for these old IDI engines.

 

[guydewdney]

Is the turbo working? Does it kickdown?

 

[merc85]

Have you checked to see if the injectors are leaking?

 

[neilrr]

It appears fellow owners of this beast (w202 model) are seeing about 35mpg. When I put £20 I am getting about 100 miles out of 15 litres so roughly about 28mpg. I have tried to alter my driving style and be more gentle with my right foot yet I have not seen any real improvement.

What could cause such poor fuel consumption or economy

Guesswork?

Brim it, drive it a few hundred miles then brim it again to get an accurate figure.

 

[mattc]

As above check it properly.

Since 24 Feb 2015 when I bought mine I have done 8210 miles. My average mpg is 40.97, worst for a tankful was 37.59, best 43.65. The majority of that is on motorway and A roads. All the fuel lines and seals were replaced just before I bought it. It starts first time on the button and Jack at PCS remarked how little my turbo leaked. I guess I am saying mine is in better fettle than most so this is about the best you are ever going to see consumption wise

 

[neilrr]

Run it on WVO or biodiesel then you won't give a flying f*** what the fuel consumption is!

 

[darkchild101]

Is the turbo working? Does it kickdown?

Yeah turbo is working or at least i think it is and it does kick down

 

[darkchild101]

Have you checked to see if the injectors are leaking?

How do i do that

 

[tim.100]

Mine has been returning about 30mpg since 1997, when it was new.

The cat was blocked but this happened very progressively, so it was hard to tell. That problem was easily resolved!

Injector cleaner might help. Also check the air filter - for some reason my Mahle filter gets visibly filthy after 6000 miles, so I change it twice a year.

There's a old thread on this forum about the inlet pipes:
http://www.mbclub.co.uk/forums/engine/2929-oily-inlet-manifold-pipes.html

I have never done the above cleaning, but let us know if you do.