2009 Jetta 77kw TDI with dsg (1.6 loitre)

[rory]

Just a bit curious about the computer display re consumption; instant and average.
Read a few threads which seem to indicate the readings are nearly always "optimistic" with some folks suggesting they should be taken as a guide only.
I check every time I re fuel and find the average consumption displayed has always been 100% spot on.
Now the computer speedo reads 6.5% high through the range;as per check by 2 Garmin gps s simultaneously ( the "needle" speedo reads 8.5% through the range -even worse)
Because I use the tripmeter kilometers to calculate my fuel consumption check, and it adds up; must I asssume that these kilometers are "fattened" by 6.5% ?
And am I being brought in for a 15,000 kilometer service at just over 14,000ks?
Anyone care to comment?

[Maverick]

Just a bit curious about the computer display re consumption; instant and average.
Read a few threads which seem to indicate the readings are nearly always "optimistic" with some folks suggesting they should be taken as a guide only.
I check every time I re fuel and find the average consumption displayed has always been 100% spot on.
Now the computer speedo reads 6.5% high through the range;as per check by 2 Garmin gps s simultaneously ( the "needle" speedo reads 8.5% through the range -even worse)
Because I use the tripmeter kilometers to calculate my fuel consumption check, and it adds up; must I asssume that these kilometers are "fattened" by 6.5% ?
And am I being brought in for a 15,000 kilometer service at just over 14,000ks?
Anyone care to comment?

The odometer is close to spot on, only the speedo has error introduced as per UN/ADR requirements. You can read more about it on my website at my-gti.com and search on "speedo".