I've just bought a 2003 S-Type 2.5. I'm very happy with the car but I have a question about the trip computer's fuel consumption reports that appear to be somewhat bizarre when idling:

When standing still and the engine on idle, the current fuel consumption is reported as 99L/100km (or 0 MPG in imperial units) which sounds a bit worrying as most trip computers I've seen (unfortunately no Jaguars, though) will report something along the lines of "0 L/100km" or "--L/100km" in the same conditions. Of course, the short-term average consumption will quickly rise to ridiculous numbers if I reset the trip computer for a new trip, meaning that any short trip will present with inaccurate and unreliable numbers.

Anyway, whenever I start slowly moving the car forward, the numbers will slowly decrease from the 99L/100km to slightly more realistic numbers but until the car gets a marching speed of a few km/h, the numbers remain very high.

I phoned the seller who was able to try another S-Type at his end. It displayed these same strange consumption numbers.

My question now is if this is normal behaviour for the trip computer? Why does this happen and, if it isn't normal, what can be done to correct the problem? One would think that the fuel consumption of an engine on idle would be reported as very low.

As for the real consumption, I don't really have any numbers yet, as I just bought the car.

I'd appreciate any input.

 

It makes sense to me, it's reporting miles per gallon. If you are at a stand still you are not moving thus no miles or km per gallon/liter

 

Yeah, why would you expect anything else when you're doing zero miles per (any amount of fuel)?

If you want a different reading, don't have it set to display the instantaneous reading

 

This has been my experience on all of my vehicles that have had on-board computers. This ranges from Audi, Cadillac, Chrysler, Ford, and now Jaguar.

 

odeon, your computer is acting normally as Jagv8 stated. Relax and enjoy your car.

 

As others have said, this is normal and is probably accurate too. If the car is stopped, you are travelling 0 miles while consuming 1 gallon of gas. How could that be wrong?

 

I guess I haven't thought this through properly after all. Thank you, all, for your input.