Erratic MPG Readout

[helooooo]

Hi All,
My MPG readout as far as I have noticed in the week or so of having my MK4 Golf 1.8 T GTi has been very stable. But tonight when driving home it was jumping all over the place, it was as high as 70MPG at one point. I was't driving silly speeds.

Im just wondering, I reluctantly gave someone a jump start the other day and its the first time I have looked at the battery on this car with different connections ive seen on my previous cars so im wondering if I have done any damage to the ecu or anything else? 

Also does anyone know why I have a number 1 always in my computer display? it doesnt seem to represent anything like gear number or anything? if it is supposed to be gear number it doesnt change, what could this be? Thanks

[Rhyso]

you have two types of memory on the MFA

1) is your trip computer and resets 2 hours after you last drove the car
2) is your long term average and resets after 99 hours 99 minutes.

to change between the two on your wiper stalk is a button on the bottom. hold this down to move between the two memories

the erratic MPG display you are reffering to is mostly likely your real-time MPG.  to see your average MPG for the trip use the buttons on the END of the wiper stalk to cycle through the display.  you can view miles covered, time, average speed and your real time MPG.

Hope that helps 

[ub7rm]

If its instantanous MPG then thats perfectly normal, it give you a pretty good idea of MPG if your cruising along but if you touch the brakes or give it some welly or anything then it varies greatly between say 12mpg when you boot it and 200 MPG when you crest a hill and start rolling down the other side.  I think there was a topic on this before when most people reckoned it was more of a random number generator!  Average MPG is pretty accurate though I would say.

HTH

[arnoldlog1]

it's a random number generator, it's only use is for putting ur lucky dip on, for the lottery. 

[helooooo]

to change between the two on your wiper stalk is a button on the bottom. hold this down to move between the two memories

Hmm the button under the stalk was a reset button which did nothing however on the end of the stalk was and up/down button which allows me to change between options. looks like I must have pressed it by mistake. Thanks for the replies guys

[Rhyso]

sorry mate i got it wrong  :embarassed:

to change between memories press the reset button once DONT HOLD IT DOWN lol