Fuel Computer Tells Big Lies...

[steveDSG]

I have done a little over one thousand miles in my 2.0 diesel DSG and thought I would give the car a proper MPG test. I filled the car and drove steadily from South Yorkshire to Whitby and back via Scarborough and filled the car again on arriving home. The computer told me I had averaged 59 MPG for the journey, after filling the car up I calculated the MPG based on the amount of diesel used and the true figure was 50 MPG.

A big difference, the computer claims 20% better than real MPG. My real MPG is decent but I am surprised by how far out the computer is, most of my other cars have been very accurate or within 5%.

How do your computer figures compare to reality?

[dippo]

My CR 170 DSG has done just over 1000 miles from new. The computer tells me that I'm getting 41.0 mpg; fuelly tells me 34.9, so mine's only 17.5% optimistic!

[ddyer79]

I have done a little over one thousand miles in my 2.0 diesel DSG and thought I would give the car a proper MPG test. I filled the car and drove steadily from South Yorkshire to Whitby and back via Scarborough and filled the car again on arriving home. The computer told me I had averaged 59 MPG for the journey, after filling the car up I calculated the MPG based on the amount of diesel used and the true figure was 50 MPG.

A big difference, the computer claims 20% better than real MPG. My real MPG is decent but I am surprised by how far out the computer is, most of my other cars have been very accurate or within 5%.

How do your computer figures compare to reality?

My 170CR DSG was about 8% out and my current 3.6 V6 slightly less at about 7% optimistic.

There are many threads on here to tell you how to correct this using VCDS and many wiling to help.

[Coops]

As said this can be corrected in VCDS. Mine also runs slightly out, c8% I think, but I track my fuel via a Fuelly account.

[Gizmo]

Mine was 10% optimistic before i calibrated it with VCDS.

[Yue04]

My 170cr dsg is saying 52.1 and actual is 49.15 so nearly 6% out. Will now endeavour to get it calibrated through vcds now.

[xreyuk]

Mine under reads by about 1-2mpg (9000 miles on my Seat Leon now). So if my computer says 60mpg, I'm actually doing between 61-62mpg.

[Kiwibacon]

I have done a little over one thousand miles in my 2.0 diesel DSG and thought I would give the car a proper MPG test. I filled the car and drove steadily from South Yorkshire to Whitby and back via Scarborough and filled the car again on arriving home. The computer told me I had averaged 59 MPG for the journey, after filling the car up I calculated the MPG based on the amount of diesel used and the true figure was 50 MPG.

A big difference, the computer claims 20% better than real MPG. My real MPG is decent but I am surprised by how far out the computer is, most of my other cars have been very accurate or within 5%.

How do your computer figures compare to reality?

Not being from the UK, I have no idea what that distance is. But MPG averages work best over 3 or so fill-ups, even better to keep a running tally. A single fillup can be wildly inaccurate due to everything from the speed of the pump to the temperature of fuel in the tank.

[unclerichy]

10% over-optimistic here. Just the same as my old Octy. The Wife's Fabia is generally spot on.

[Tankdave]

Mine was about 7% on the happy side too, but VCDS sorted it.