E320CDI w211 Poor fuel economy

[aka$h]

Now the s-class is fixed (thanks again to the chaps who pointed me in the right direction), the time has come to sort the e-class out.

The car seems to give me very poor economy compared with my E270.
Yes its an extra cyclinder, but at 80mph the 270 would give me a around 42mpg, and this one gives me around 34. These were takend once cruise was on the the computer reset. Looking at other threads, it seems this is lower than it should be.

Again, DAS shows no faults, power seems fine. First thing I guess would be to change the MAF.

Any Ideas?

 

[BlackC55]

Are the filters clean?

Is the engine oil in good shape?

Tyres at operating pressure?

All else fails try an air mass

 

[aka$h]

Are the filters clean?

Is the engine oil in good shape?

Tyres at operating pressure?

All else fails try an air mass

Ill check those out,
The air mass on this model is £200
It was only £60 on the s320cdi, ill try everything else first.

Thanks

 

[DieselE]

Now the s-class is fixed (thanks again to the chaps who pointed me in the right direction), the time has come to sort the e-class out.

The car seems to give me very poor economy compared with my E270.
Yes its an extra cyclinder, but at 80mph the 270 would give me a around 42mpg, and this one gives me around 34. These were takend once cruise was on the the computer reset. Looking at other threads, it seems this is lower than it should be.

Again, DAS shows no faults, power seems fine. First thing I guess would be to change the MAF.

Any Ideas?

My car gives me roughly the same economy as you were getting with your E270. I notice from your signature that you've had the car chipped. Could that be the cause of the higher consumption? Just a thought.

 

[aka$h]

My car gives me roughly the same economy as you were getting with your E270. I notice from your signature that you've had the car chipped. Could that be the cause of the higher consumption? Just a thought.

Thats what I thought, and have swapped the ecu back for the original one, when cruising along it seems to make no difference.