Good move Chop - LPG is ace!

67litre tank is not so good though Especially if thats its total volume, as you get 20% less than this as actual LPG capacity, thus only 53.5litres (11.78 gallons)

I've no idea what sort of economy you can expect out of a 3.0litre X5, perhaps 20mpg - 25mpg, which would give an approx range of 235-295miles on a tank.....

Only a problem if you're doing quite a few miles every day as like me, you'll end up in the petrol station re-fuelling every 2-3 days

The maths above isnt quite accurate either, as you get slightly LESS economy on LPG than you do on petrol, so its not quite as simple as 70refills before you break even.