Oddity, "Long Term" average fuel consumption on MFD

[ChrisG]

As you all probably know when selecting the trip computer's average fuel consumption display, you can toggle between 3 different averages, "Since Start" which is from last engine cold start, since refuel which is obviously the last time the tank was refulled, and then "Long Term" which I always assumed to be an ongoing average from new / from last time you reset it?

Tonight though, whilst driving home in our 3000 mile old 1.4 FR ACT ST, I selected Long Term average which has never been reset and said something like 39.3mpg which is roughly the figure it's always been on when I've flicked to it before, but then in the space of 10 miles leaving it as the selected display, it crept up to over 45mpg!

So... I'm either misunderstanding what that display is trying to show me, or I or somehow inadvertently reset it when I selected it mid journey because there's no way an average of 3000 miles can change so drastically in 10 miles, anyone care to enlighten me?!

 

[concerned cat]

It resets itself after 100 hours.

 

[thefunkygibbon]

It resets itself after 100 hours.

really? what 100 hours of driving time it just goes back to 0/0/0 ?

my long term is only at 50hours total driving time and 1300 miles. If it resets then i'm going to be pretty annoyed as i was hoping to get a nice stats of having the car for a year.

 

[chrisRibiza]

Yep it will reset to all 0's and start again after 100hrs of driving.

 

[thefunkygibbon]

how crap

 

[ChrisG]

Weird, I can see why it might keep a long term average over the last 100 hours or so, but to reset like that seems odd. How can you tell how many hours you've driven?

 

[thefunkygibbon]

its on the main screen. press the 'car' button and scroll to long term. stats are all there

 

[jimiC]

yep, im a little disappointed too with the short time length. i managed just over 3000 miles before it reset, this compared to 38,000 over almost 900hrs on my previous brand's computer which wouldn't reset unless I deliberately did it.

 

[ChrisG]

its on the main screen. press the 'car' button and scroll to long term. stats are all there

Thanks, yeh that explains it all. Just had a look and the long term time says 30 minutes, the journey back from the parents is ~25 mins so it must have reset just as we arrived and I happened to be watching it on the way home at only 15-20 minutes into its new average. Odd ways to do it but now I know!

 

[Albie999]

Oh that is annoying. I thought I may have somehow reset the longterm (maybe holding my finger on the button to long). I was hoping, similar to my other car, that it would never reset and it would let me know how much I had been doing since I had the car (done 16k in 8 months)

 

[Fred99]

From my experience, the figures you get from the MFD are very optimistic. I use Fuelly to get a totally acccurate figure.

http://www.fuelly.com/car/seat/leon/2013/fred99/247551

 

[ChrisG]

I think the MFD figures vary from car to car, I've checked ours and it's about 1mpg optimistic from direct calculations, but others from what Ive read are far more optimistic. ISTR reading somewhere that there might be a way to calibrate / error correct it using VCDS, but not sure.

 

[Fred99]

It is probably related to the fact that the speedo is optimistic - this is usually deliberate. Mine is about 6% optimistic based on GPS and the consumption about the same.

 

[Seastormer]

It resets itself after 100 hours.

Rubbish, the long term resets itself at approx. 2000 miles, as stated in handbook, I an on my 2nd auto reset from new.

 

[concerned cat]

Rubbish, the long term resets itself at approx. 2000 miles, as stated in handbook, I an on my 2nd auto reset from new.

I think, as substantiated by others, you'll find I'm right.

 

[Seastormer]

I think, as substantiated by others, you'll find I'm right.

Funny mine both around the 2000 mile mark, the 100 hours must have been around the same mileage twice then, my mistake.

 

[kazand]

Perhaps it's 2000miles or 100 hours, whichever occurs first..... Not looked at ours tbh, only concerned when fuel gauge goes red as it needs filling up.....

 

[Fred99]

I think, as substantiated by others, you'll find I'm right.

What the handbook actually says is:-

The memory records the values for a specific number of partial trips, up to a total of 19 hours and 59 minutes or 99 hours and 59 minutes, or 1999.9 km (or miles) or 9999 km (or miles), depending on the model of instrument panel. On reaching either of these limits, the memory is automatically erased and starts to count from 0 again.

So, it could be 2000m or 100 hrs.

Mine resets at 100 hours.

 

[andrewpain]

hardly long term, is it?
since last service might be just about acceptable, but "since forever" would be better....

 

[concerned cat]

hardly long term, is it?
since last service might be just about acceptable, but "since forever" would be better....

I think I'm right in saying all VAG cars are the same. I know my last few VW's were.