Fuel computer

[A8 PMJ]

My first post on the Jaguar forum. Please be gentle with me. I recently bought a beautiful 2002 XK8 coupe, but I am confused by the fuel computer, in particular the instantaneous reading. At a constant speed on level ground it can hunt from 17mpg to 35mpg and when I lift off for say a roundabout it will go to 70 or 80mpg but then drop to 18mpg for no reason and then go back to 65mpg. Is this normal or do I have a problem?
cheers
Pat

[james S]

Quite normal

[A8 PMJ]

Thank you James.
Pat

[Triple7]

As with most fuel flow indicators, this is giving you the actual fuel flow through the fuel metering unit or through the fuel injectors. The best guide is the average fuel consumption read out on the trip computer.

G

[Jaguar steve]

I've stopped using mine now petrol is over £1 a litre.....