Poor Consumption All Of A Sudden - 3.0 Tdi

[Djwoody]

Hi.
I noticed this morning on my way to work I got an average consumption of 35mpg.
Every other morning I have been getting 47mpg+
Each time I've been driving at 65-70mph.

Is there a reason why my consumption has dropped suddenly?

Chris

A4 B8 3.0 TDI

 

[markm,]

Could be doing a regen ?

Mine was all over the place , got 47mpg on a run to work, way home was about 36mpg and with air con on the same homeward trip was 25mpg ?

 

[Djwoody]

I'll keep an eye on it tonight on my way home.
I've heard change the fuel filter or coolant temp sensor could help if there's a problem.

 

[desertstorm]

Was the car doing regen cycle ? I found with mine that it had a big effect on consumption figures.
I used to find the engine fans would be on when I parked up if it had been doing a regen.

Karl

 

[Djwoody]

Not sure if it was doing one. It's a shame there isn't a notification on the display to inform you of when one is being performed, that would be useful.
Didn't notice the fans on.

 

[Djwoody]

Well after another journey to work this morning, it has jumped up to the 40s so I assume it must have been doing a regen. Still not as good as I was getting.
Would a full service (fuel filter etc) help do you think?

 

[benjie]

A full service, in my experience, always helped the mpg a bit. Though I never owned a 3.0 TDI , I also found that the coolant temp sensor on my B6 1.9 affected fuel economy a lot, so much so that I included it in my annual servicing, so you might be on to something there. Especially if it's original to the car as it'll be getting on a bit now.

 

[Djwoody]

Well the coolant sensor is only around £10 so I may get one fitted with my next service like you said.
Wouldn't do any harm.
Anyone know if the 3.0 TDI just has the one sensor? I know some cars have two.

 

[evans1089]

I thought 33mpg at 50mph was good in my 3.0tdi lol..