I get 2 miles per litre on either LPG or petrol round town

On the motorway fully loaded and at a steady speed i get 3 miles per litre again on either fuel

Only difference I notice is a slight increase in top end power whilst on petrol

I currently pay 65p per litre LPG and petrol is around £1.30 so I see that as a 50% saving per litre when on LPG