I think the problem has been a change of gas stations that I fill up at. The first one was level, this one is on a corner and for some reason there is a slope across the entire apron.


Prior to that I found that the dash FE was showing slighlty worse FE than when calculated - fine by me.

I have been steadily decreasing fuel consumption over the last 3 months according to the dash FE 5.7 - 5.6 - 5.5 - 5.4 and this last fill showed 5.3! But on fill up calculations it was 5.7!!!

On another occasion it was the reverse - and it just so happened that I was facing the other way on fill up! That is, the filler was downhill so I ended up putting less gas in.

While I've got you there, does ambient temperature make much difference to FE?

It's been fairly cool here for the last couple of months - 45 - 50 F.