very strange consumption/smooth acceleration

[mattmk6]

not had the car long but the car takes a long time to get to temp (although i have only seen it get to 80)

when it does finally get some heat into the engine the instant consumption goes to 1mpg at idle

at the same time i loose my smooth acceleration and the fuel consumption drops through the roof when driving

turned the engine off while i was having this problem and it went away when i restarted about 1 minute later.


anyone else had anything similar??

the car is a 2007 1.9cdti signum

[paulhb]

The diesel particlate filter uses diesel to clean itself when the conditions are right and this drops the fuel consumption down considerably it returns to normal when you switch off as the engine needs to run to do it or the cycle is completed and switched off by the ECU.

[mattmk6]

thank god for that!

i should stop paying so much attention to mpg and just enjoy the car!

[paulhb]

All the diesels with DPF do it watch it on a long run and all will come good.