I wasn't going to post again on this forum as I've dumped the 1.6 lpg astra and bought a 2.0 litre mondeo diesel, but its worth pointing the following out before I leave.
My mondeo is returning 60 mpg - my astra returned an equivalent 62 mpg.
So, the mondeo, a larger car with a much more powerful engine can match the fuel cost per mile of a 1.6 lpg astra.
Ever thought about going lpg - well think again, especially with the lpg/diesel price differential being eroded away.
That's all - taraaa - forever....