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Hello i have had my is 220d for a few months now .The mpg has dropped from avg 37 mpg to 32.8 mpg. I have been doing the same runs in the car and the drop has been over the past 2/3 weeks. Anyone any ideas why and how to cure the problem. (38000 miles on the clock )

Thanks

Enda

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weather ? fuel economy drops as temps drop + darker commuting in morning & evening slows traffic therefore increasing consumption , my petrol passat is down from 34/32mpg on same daily commute

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Could be a number of reason why the mpg has dropped but nothing I would be too concerned about.

It maybe because your using the heating/air conditioning more or just heavier traffic.

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There are different diesel additives added to most diesels in winter to prevent it thickening/freezing as the cold weather hits. These additives are known to reduce mpg. Could be that the annual changeover has taken place at your local petrol station ready for winter.

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Strange but after putting diesel in the car today from a different station and driving about 60 miles the tank avg mpg is reading 43.8

(thanks for the replys)

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Most of my journeys are quite short back and forth to work, customer visits, shopping runs etc. However, every month or so I give the car a brief blow out at higher revs to clean out any carbon build up in the EGR valve. [ I basically go for a quick blast down the dual carriageway using much higher revs than normal and revving higher between gear changes]

Thus far it seems to be working. My average on a 2000 mile trip, encompassing all types of driving and terrain, around France was 48.8mpg. Back home now on the work run it is holding at 41.9. Strange that... identical to Matus' mpg quoted figure.

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Dirty EGR valve?? Check and clean maybe??

Col

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Dirty EGR valve?? Check and clean maybe??

Col

Think i will have to give it a try.

Cheers

Enda

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Low tyre pressures?

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Most of my journeys are quite short back and forth to work, customer visits, shopping runs etc. However, every month or so I give the car a brief blow out at higher revs to clean out any carbon build up in the EGR valve. [ I basically go for a quick blast down the dual carriageway using much higher revs than normal and revving higher between gear changes] Thus far it seems to be working. My average on a 2000 mile trip, encompassing all types of driving and terrain, around France was 48.8mpg. Back home now on the work run it is holding at 41.9. Strange that... identical to Matus' mpg quoted figure.

Agreed. My average MPG over 8000 miles since last service is 41.7!

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I cleaned the egr at the weekend so will wait to see what the mpg avg is in a week or so.

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I cleaned the egr at the weekend so will wait to see what the mpg avg is in a week or so.

So the burning question is.....

Was it really quite dirty/gunked up with carbon deposits ( I'm trusting it was)??? Cos' if it was quite clean then nothing is likely to be achieved.

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I cleaned the egr at the weekend so will wait to see what the mpg avg is in a week or so.

So the burning question is.....

Was it really quite dirty/gunked up with carbon deposits ( I'm trusting it was)??? Cos' if it was quite clean then nothing is likely to be achieved.

It was quite dirty .

Everything was caked in about 1mm/2mm of carbon.

Just hope it makes a difference now it is clean.

Thanks Enda

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Not sure if 1-2mm of carbon build up would drop the MPG. I've seen photos on here that show the 20mm bore below the valve reduced to 5-8mm from the carbon build up. Sure let us know how you get on.

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