Guys,

I am starting to doubt the mpg readings I'm getting in my '56 plate standard Fabia vRS......on a 300 mile motorway trip it told me that I averaged 67.1mpg but driving 10 miles into work, stopping and starting in traffic, it tells me I averaged 69mpg???

Any ideas? Could the reading somehow be incorrect?

Cheers,

Dan

That doesn't sound believable to me , unless it's all down hill with no traffic lights.

On a long motorway run at 56mph you might get your 67mpg but if you were doing a more normal 70-75 then there's no chance at all.

You'd need to do some manual calculations on how much fuel you put in to be certain but I think you have a problem.

The trip computer will read out slightly, I think it works on the basis of the last 2000 miles driven and works out the mpg from there, I do know there is a website where you can work it all out but not sure on the link to this.

Hope this helps.

I recently did a 440 mile journey. I was doing well over 70 mostly around 90 to 100 and the trip computer reported 72mpg at the end of the journey.

When i filled up I worked it out to be 53MPG.

I'm going to try and adjust it via VAG COM as nearly 20MPG out is ridiculous.

Mine is a VRS 2006.

The motorway mpg seems bout rite i get well up into the 50/early 60 mpg on the motorway but prob is when you come off the motorway the mpg doesnt go down untill it resets i find. as said above it works it out over so many miles around town i normally get about 38-40mpg if i drive normally but i find it quite accurate to be honest

My computer isn't too bad,

Overall average on the computer works out at about 59mpg on each tank, and manually doing it, it works out at about 53mpg...

My trip computer is out by exactly 10%.

mine is quite accurate at around 3% out

My last 2 checks recorded Trip 2 readings of 60.2mpg (over 322 miles) and 73.2mpg (over 402 miles) whereas brim to brim mpg figures were 47.13mpg and 53.93mpg respectively, ie my car's trip is around 25% in error.

I would add that the odometer reading is accurate to within 1% of GPS mileages as checked on a number of long journeys of known distance.

Edited 3 October, 200817 yr by DGW

i just used this MPG calculator UK miles per Gallon - calculate MPG

and i got

distance covered = 688 miles

Litres used = 55L

Cost per litre = 1.17p

gives me 56.92 MPG and my 2nd trip comp said 57.3 so thats not too bad i thought

Mine is ridiculously bad. Approx 35% out!

buy why is mine more accurate than others, mines a 2004 vRS

the trip comp has two MPG modes, one for instantaneous 'what mpg at this precise moment in time' and one for the average over the last trip which will include all driving where any gaps do not exceed two hours whereupon it will reset automatically(iirc).

If you swap mode to long term by quickly dabbing the reset button once, the second 'max two hour gap reading' goes in to a reading based over a longer term which resets itself every 100 hours of driving (iirc) so do be careful which reading you are using. Its all detailed in the handbook.

But the thing definitely is not accurate!

HTH

the trip comp has two MPG modes, one for instantaneous 'what mpg at this precise moment in time' and one for the average over the last trip which will include all driving where any gaps do not exceed two hours whereupon it will reset automatically(iirc).

If you swap mode to long term by quickly dabbing the reset button once, the second 'max two hour gap reading' goes in to a reading based over a longer term which resets itself every 100 hours of driving (iirc) so do be careful which reading you are using. Its all detailed in the handbook.

But the thing definitely is not accurate!

HTH

thats right,

i reset number 1 function on filling up and number 2 function,

number 2 gives me the overall and number 1 for that journey or for journeys with no big break in between

but the number 2 trip average mpg reading was not far off what i worked it out to be,

No2 in my experience never resets itself...

but if you keep your finger on it it goes back to 0 and starts counting no1 mpg,

My last 2 checks recorded Trip 2 readings of 60.2mpg (over 322 miles) and 73.2mpg (over 402 miles) whereas brim to brim mpg figures were 47.13mpg and 53.93mpg respectively, ie my car's trip is around 25% in error.

I've seen mention of fuel computer errors on remapped cars . but not on standard ones to this extent

I saw 72mpg on a trip to the Lakes in August, on the way there and on the way back, with about 30 miles at about 60mpg in the Lakes. Filled up and checked the real values when we got home - 55mpg!

Mine is WAY off - Long Term average is 58ish, I get 45-48 at the pump, the compie is pants - waste of time and when I got it checked the dealer said -

'We can find no fault, Sir'.

I recently did a 440 mile journey. I was doing well over 70 mostly around 90 to 100 and the trip computer reported 72mpg at the end of the journey.

When i filled up I worked it out to be 53MPG.

I'm going to try and adjust it via VAG COM as nearly 20MPG out is ridiculous.

Mine is a VRS 2006.

53 MPG is pretty impressive for those speeds.

On my last tank I averaged 43MPG at the pump - that was with the trip comp reading 55 + most of the time and several 40 mile trips reading 70MPG + (where I was experimenting with hypermiling).

The trip comp in my standard 54 vRS is v good on the whole. The last several tanks look like this

Calculated mpg-Comp mpg

45.2-47.24

48.1-48.2

46.8-48.8

46.7-47.2

47.1-49.0

47.9-45.9

48.2-53.0

53.4-53.3

50.4-51.8

47.5-47.9

My trip computer's a pretty dozy bit of kit, but the car is remapped, has non-standard wheels and tyres, a different turbo and inter-cooler and so on. Strangely, the odometer and speedometer (compared to my sat nav) are only about 5% out.

I brim my tank on each refill, but the car refuses to recognize the extra 6/7 litres of fuel I stuff in and beeps at me when the indicator shows about 65 miles of fuel left. In reality this is about 140 / 160 miles (depending on the "briskness" of my driving style, ambient temperature, altitude, humidity, traffic, etc.)

Yesterday on a full tank it told me it had enough fuel for 435 miles, but I know this'll be 560 / 580 miles.

I don't trust my trip computer. I tested it over a 102 mile journey by filling tank before and after. Computer gave average mpg as 53 where the actual was 39! This was out of town keeping at steady 55mph for nearly all journey. Very disappointed with fuel economy on my brand new Fabia 1.2 petrol 70bhp. Am hoping it will improve, but am consulting with the dealer.

... and I meant to say it's a Fabia 2 and I was routinely getting 38 to 48 mpg tank average from my Peugeot 306 estate.

I don't trust my trip computer. I tested it over a 102 mile journey by filling tank before and after. Computer gave average mpg as 53 where the actual was 39! This was out of town keeping at steady 55mph for nearly all journey. Very disappointed with fuel economy on my brand new Fabia 1.2 petrol 70bhp. Am hoping it will improve, but am consulting with the dealer.

I had one of these as a hire car, and i was shocked at how bad the fuel economy was. :thumbdwn:

My trip computer (on an 07 vRS) is consistently 20% out. There is some fudge factor that you can set using VAG-COM, but only for earlier models. There's a thread about it somewhere on here but I can't find it at the moment.

I asked the garage about it when mine when in for it's first service and they said there was nothing that they could do about it.