Poor MPG on C220 CDI

[GMInsite]

Hi everyone, I have a 2005 W203 C220 CDI and when looking at the trip computer i am only getting 33-36mpg , My daily driving consists of 25 miles of motorway and 25 miles of single carriageway.

On the motorway i dont go about 75-80 and on the carriage way i do 60.

Temperature gauge ranges from 60-80 degrees

Is there anything i can do to increase my mpg.

Greg

 

[wemorgan]

Drive at 60-70mph on the motorway. Hold a steady speed.

 

[Stratman]

That temperature is too low, it should be nearly 90. A new thermostat is in order.

 

[horgantrevor]

air filter

 

[GMInsite]

Thermostat and a new airfilter. Anyone got a how to or a detailed photo of the thermostat where it is houses??

 

[GMInsite]

Just done 50 miles 49 of which are m1 staying at 60-65 and getting 42mpgbut temp gauge stays at 60degrees

 

[Stratman]

50 miles at 60-65 mph should be getting over 55 mpg.

The thermostat is definitely faulty. It's an easy enough DIY job, just be careful of the fuel pipes in the vicinity. They can be a bit brittle.

 

[PeterE320Cdi]

I agree the Thermostat is the most likely cause, my brother in law has the same car and was only getting 40 mpg max with low temp, had the Thermostat changed and now gets 50 mpg.

 

[vealige]

As above change the thermostat and use that as your starting point. However there are many contributing factors to poor MPG.

Tend to be incorrect tyre pressures, poorly serviced car, gearbox oil, broken temp sensors, clogged EGR or inlet manifold, leaky boost pipe joints, worn turbo vaccume pipes and of course driving style.

I don't have a Merc as my run around I use a Bora TDI and at 70-75 that returns 58-62 MPG and around town 45-50 MPG.

 

[Dieselman]

If the o/p car has a DPF, along with the stat not working, it will be that.

 

[GMInsite]

Yeah it has a dpf. Can i just use a dpf treatment see if it cleans it out? Ill try locate the thermostat today and grab one tomorrow.

Transmission oil is next on the cards as well dont know whether to tackle it myself on a ramp or get a garage to do it.

 

[gIzzE]

Your DPF will not regenerate until it gets to temperature, which is 91ºc from memory, however, if you have a knackered thermostat the car will never get there and your DPF will get more and more blocked and then fail.

Loads of BMW owners who have had DPF fail have then changed their thermostat and suddenly it regenerates and is fine again.

The thermostat needs to be a serviceable part nowadays as it is so important.

 

[GMInsite]

Anyone know a rough price from dealers? Can only see a circoli one in ECP for £41.

Can anyone point me in the right direction in the engine bay.

 

[gIzzE]

I think I paid £28+vat for mine a few weeks back.

 

[gIzzE]

Get the original one, some of the others don't get up to temperature and fail pretty quickly.

 

[GMInsite]

Ok will pop into my local dealer tomorrow.

Thanks

 

[GMInsite]

Wheres it located?

 

[Stratman]

W203 C270 thermostat change (The C220 will be very similar) It's a lot easier than than it seems when you see it all written down.

Picture 3 in the linked article shows the location. Follow the top hose from the radiator back to the engine, it connects to the thermostat. Note that the holes where the bracket screws in may not be tapped. You just screw hard, using the existing screws to cut a new thread.

 

[gIzzE]

Ok will pop into my local dealer tomorrow.

Thanks

Wheres it located?

Riverside Business Park.

 

[GMInsite]

I ment thermostat. I work in mk so will go kingston.

Got a haynes manual today for future jobs