| How many miles a year do you do, and how long do you plan to keep your car?
55p per litre may sound attractive on its own, but the miles per gallon when running on LPG will be considerably lower than on petrol, so you'll be filling up way more often.
Add to that the conversion cost and inevitable loss in value come resale time and it may not be worth doing.
You'll also need to take into consideration any warranty implications, as the conversion won't be MINI approved. | 
