Any use additives..?

Hi all
I was just wondering if anyone uses any form of additive -particularly ones which are just added to the tank?

If so which ones and are there any preferred/recommended ones for an older engine(like my 94 plate Uno) ....??

Pete

Only additives I use are optimax over standard petrol and shell diesel extra over supermarket diesel - its actually cheaper here now too

Thats an interesting thought-does anyone only ever use Premium Unleaded..?and do you see any real benefits?

See above