MPG issue since changing VRS DPF sensor

[joeninho]

Hi folks,

 

I think I have an issue with my car at the moment.  It's a '59 VRS TDI CR 170.

 

A few months ago I changed the DPF pressure sensor, as I had the emissions light on regularly.  Several people on here provided the necessary advice and guidance, so I know I have fitted and calibrated the part correctly, however, another issue has developed since...

 

The car now reports an MPG figure of 36-37 MPG.  Before I changed the sensor, it used to report around 44-47 mpg, which I can live with, but I'm feeling a little short changed at the moment.  There has been no change in my driving and the 30's figure is largely based on motorway/A road driving.

 

When I filled up a few months ago, the dash would report an expected mileage of 600+ on a full tank, however, it now reports an expected mileage of 475 when I fill up.

 

Any ideas on what may be wrong?  Or what I can do to improve things?  Or even a list of possible things to check?

 

Cheers,

 

Joe.

 

 

 

 

[Antofa]

600+ on a full tank?  I'd  feel lucky getting 500!  475 would be more likely with mixed driving... Unless you drive everywhere at 30mph.

 

I'm happy that my fuel consumption readout is accurate and not giving wildly optimistic mpg figures. It's always best to gauge it against the true mileage you get  on one tankfull.

[wolvotim]

My 62plate CR is returning about 40mpg now the weather has cooled down. In the summer it was reporting 44-45 and doing about 500miles on a tank. My wife mainly uses ours for school and shop runs as I have a van for work

[littleade]

Mines dropped by about 5mpg due to the cold weather and IIRC the suppliers will have switched to winter diesel now which I don't think gives as good mpg results as summer diesel. Have you done a brim to brim calculation rather than just rely on what the computer is saying? that way you'll know where your issue lies.

Cheers

[RobM]

joeninho - Regardless of the MPG displayed, have you noticed the actual fuel consumption drop? Are you suddenly finding the needle drop quicker than usual? It could well be the reporting that's wrong, rather than decreased fuel consumption itself.

 

If your MPG has indeed dropped, I'd suggest a faulty sensor. My 170 CR is getting 45-50 with A-road and motorway driving at the moment, so long as I stick to speeds below 80MPH!

[joeninho]

Thanks for the replies folks.  On a full tank I get around 420 miles, so if that's normal, I'm happy enough with that.  I'm just a bit surprised at the dramatic change in the reading from the dash.  I'll stick with it for now and see what happens.  The car was serviced/MOT'd a few weeks ago, so everything should be tip top.  I'll double check the tyre pressure in case that's costing me a couple of mpg.

 

Thanks again for the advice.

 

Joe.