Accuracy of fuel consumption on MFD

[pcs7038]

I’ve had a niggling suspicion for a while that the fuel consumption shown on the MFD didn’t look quite right, so I’ve tracked it over a couple of months:

The MFD shows cumulative consumption over the last 3000 miles to be 55+ mpg; distance recorded and actual fuel purchased comes out at just under 51 mpg.

Anyone else experienced similar discrepancies? If I ask the dealer to look at it, will I get any anywhere?

[Ivan-DK]

Mine MDF is also a little optimistic

[Tankdave]

Mine is 7% optimistic

It is adjustable with a VCDS thingy

[laaban]

Last time I fueled up MFI shoved 6,9 l/100km. But the actual measure was 7,7.

That's just above 10 % optimistic and way off IMO.

Going to re-check at next fuel up.

[Gizmo]

Mine was 10% optimistic

It is adjustable with a VCDS thingy

It is now spot though on after I calibrated it with VCDS

Don't think you will get anywhere with the dealer TBH.

[Departed]

Don't think you will get anywhere with the dealer TBH.

I'd bet on it! They won't even consider firmware upgrading, let alone "tweaking" for accuracy.

Following Gizmo68's example, mine's spot on now, thanks to VCDS adjustment.

Ray

[AigariTTO]

Superb V6 MFD shows 10.7, but it is more like 11.5-12 most of time city driving

[BilboBaggins]

On normal driving for my 1.6CRHatch the display shows about 55.6mpg while brim to brim is 53.3-about 5/ difference

[danmooney]

It bemuses me that the figures are so massivly inflated. I see a couple of you have changed it with the VCDS. Is there a previous post on here of how to do it?

I regularly get get 62mpg+ on the display but hit a pretty constant 55.4mpg brim to brim. As for the 800+ miles it says I will get when I have a full tank. Dream on MFD!!

[Justin Case]

It bemuses me that the figures are so massivly inflated. I see a couple of you have changed it with the VCDS. Is there a previous post on here of how to do it?

...

Here´s a link from the Octy section My link

[Richf]

Its never going to be accurate , not even the speedometer or odometer is accurate so the mfd doesnt stand a chance

Waste of time calibrating it imo

[skodanut]

I did a nice steady run from portsmouth to stevenage and back the other day, and the trip computer on my greenline display showed 76mpg and we was doing 60mph all the way there and back...apart from driving into stevenage and back out again

I put £32 quid in and the tank showed that we had approximately 150 miles left when we returned...i thought that was pretty good going considering it was a 130 mile drive one way.

[majland]

Its never going to be accurate , not even the speedometer or odometer is accurate so the mfd doesnt stand a chance

Waste of time calibrating it imo

If i had VCDS/VAGCOM (or one in the neighborhood) i would also calibrate it ... Also the speedo. It is annoying having to use the GPS for speed when the superb has such nice instruments ...

(Danish fines are in steps of 10% so is is almost twice as expensive to be measured at +11% enstead of +9% - So usually I set the cruise speed just below a step in the fine table. And at +30% you start to risk points on your license - so i set the the cruise speed on normal roads with 80km/h limits below 104km/h)

On my motorcycle i have "home" build fuel measurement system (http://www.enduro-stammtisch.de/module/spm.htm) - Its accuracy is about 1%. Can't see why the skoda shouldn't be just as accurate

Edited 7 July, 2011 by majland

[pcs7038]

Thanks all for the responses. I think I just need to live with it and discount the reading.

[Ozsko]

Thanks all for the responses. I think I just need to live with it and discount the reading.

I couldn't be bothered if it is accurate or not as I only use it for one reason and that is to compare what it does from one tank to the next. As long as the readings are consistent I haven't got an issue. As for 76mpg my diesel wouldn't do that down hill with a tail wind at 60 mph.

[propitious]

mine is 10L/100Km, but MFD showed 8.5L/100Km, it is a big gap between 10 to 8.5

[Guest]

I couldn't be bothered if it is accurate or not as I only use it for one reason and that is to compare what it does from one tank to the next. As long as the readings are consistent I haven't got an issue. As for 76mpg my diesel wouldn't do that down hill with a tail wind at 60 mph.

I agree, I also have two GPS speedos both show that the cars speedo is 2mph fast so the only thing I find reasonably accurate is the speedo. As to adjusting avg fuel with vcds, this will only give accurate reading on the same run, weather, ( humidity, raining, dry,wind direction temperature )load, perfect foot control road surface, traffic.

We used to fit test tanks to vehicles, do the same run over and over in all conditions summer and winter getting the same reading was impossible.

[Gizmo]

As to adjusting avg fuel with vcds, this will only give accurate reading on the same run, weather, ( humidity, raining, dry,wind direction temperature )load, perfect foot control road surface, traffic..

Sorry but I have the last few months worth of fill ups to prove that is nonsense, the maxidot consumption is now always within 0.1mpg when compared to fuelly (using the brim to brim method).

[Alvaro]

The MFD is quite exact. The problem with fuel comsumption is the fact that petrol is very volatile (you even can see it evaporating when refuelling a tank...). The times I have done about 700-800 km in a single day and I have had to refuel the same day, the MFD data were correct (by the way, I always write down the litres and the mileage, and then put them into an excel file, so I have all my comsumptions). But when there are some days between the refuellings, there is a little error (about 5-6 %), which I think it's originated from petrol evaporation.

[Stumpi]

So far my CR 170 Combi as only returning around 46 (on a run) but it is only 2000 miles in, I'm hoping it'll improve when it loosens up a bit.

[Turbostar170]

Agree with the general tone and not the optimistic chap with the 'volatility issue' My Superb 170 is saying 50mpg give or take and yet brim to brim it is about 8% optimistic. This is exactly the same as the MFD on my previous Scirocco 170TDi which incidentally was about 5mpg worse than the Superb with exactly the same engine.....!

[laaban]

I blew a whole tank in one day ans still about 10 % optimistic MFD, so no volatile I think.

People can very well say that this is ok, but why shouldn't the flow transmitters be accurate. Isn't that even better?

An other thing... When I'm rolling down a hill at let say 80 km/h in neutral it shows consumption of 1,2 l/100km (or something around) and if I'm rolling in drive it shows 0,0.

Any reason for this?

[Farnz]

An other thing... When I'm rolling down a hill at let say 80 km/h in neutral it shows consumption of 1,2 l/100km (or something around) and if I'm rolling in drive it shows 0,0.

Any reason for this?

When you're in neutral, the car burns fuel to keep the engine turning. When you're in drive, the wheels turn the engine, so it doesn't need to burn fuel to keep the engine turning.