So I normally disregard the trip computer and leave it off. It doesn’t help my enjoyment of the car at all. Recently, however, it has decided to be far more supportive of my side of the equation!

Now it indicates that pressing harder on the fun pedal increases my mileage and releasing it drops the mpgs.

I honestly don’t really care what mileage I’m getting as long as its fun, but I must admit that this way it does encourage me to tromp on it more. For science.

Anyone know a possible reason for the reversal of its normal attitude?

 

Do you have it set on km, not miles? Fuel economy in metric is measured in litres per 100 km, so a small number indicates excellent economy, and a big number indicates poor economy.

Metric uses volume per distance, US units are distance per volume.

 

Funny thing is, everywhere in the world the XJS trip computer shows mpg or L/100km, except in Japan, where it's km/L.
Volume over distance isn't Metric per se, as kilometres per litre is also Metric, but a recent-ish change to international standards.

 

I didn't know that until now. I just checked the parts book and sure enough there is a USA spec, Japan spec and rest of the world spec. Is km/L customary in Japan?

 

Yup. Standard. I've never had to deal with L/100 km, and find it rather confusing and unnecessarily complicated. Why change?

 

I don’t know how I switched it to km, but that was the case! Thanks guys! Now it’s off so I can ignore it some more.