VAG fuel computer

[cobalt]

I've recently bought a 3 year old 2.0 Tdi A4 and, according to the onboard computer, am getting an average of 42mpg from a tank. When I work it out based on a brim to brim fill up though, I get more like 35mpg. Anyone know if this is typical of manufacturers' fuel computers trying to make owners 'feel better' about their economy?

[TonyHetherington]

I have a '54 plate Audi and I've worked out that the car's 2mpg over (says 19, actually 17).

[cobalt]

I take it your A4 isn't diesel then! See you're a Lotus fan. Me too. Ironically my Elise does better mpg than my sensible car lol

[TonyHetherington]

yeah I've gto the 4.2 V8 S4 - fortunately I only do 9k miles a year so the bad MPG isn't as crippling as it could be

You have good taste! I remember my Elise (111S) used to do ridiculously good MPG - and most of those miles were thundering up the side of mountains or similar! The joy of lightweight! But then, lightweight didn't have heated seats and an entertainment system. Or a boot, come to think of it :hehE:

Really did enjoy my Lotuses though - sure I will have one again at some point

[Kevin VRs]

In my experience the 1.9 TDi single cam trip computer is pretty much spot on, the 1.9 TDi twin cam is an optimistic joke (about 25-30% over) and the 2.0 TDi is about 10% optimistic. My Octavia Scout averaged 43-44 mpg in real terms, trip always said around 48 mpg. Fabia vRS averaged around 50 mpg, trip always around 65 mpg. Current Octavia spot on at 50 mpg.

[phumy]

On the old quattro turbos (81 -91), which i believe were one of the first Audis to have MPG ometers, there is a series of "dip" switches inside the dash which can be adjusted to recalibrate your MPG ometer and it is possible to get it bang on, however requires removal of the dash cover which is a bit of a scarey job in the first place.

[cobalt]

It's not just me then. Could be worse - could be getting 20mpg out of a 3.0tdi Q7 which costs £130 to fill