lpg conversionson the on whole dont work to well on smaller engined cars as the lpg dosn't produce as much power as petrol and the freelander is a bit heavy.
the best you could expect would be about thirty to the gallon taking it steady 50-55mph
Also there are some dodgy conversions get it checked by a Auto Gas installer .
And a tank in the boot space restricts your carrying ability ,under floor is better but smaller.
On ebay a conversion of this sort is about £1700 drive in drive out
Some here would say thats probably more than a freelander is worth
but dont let that put you off .
Iv'e had lpg for a while now and at 39p a ltr its cut my fuel bill by at least 50%
you pays your money you take your choice
just remember its not a GP car!