To re-phrase the last 2 posts - unless you're in a diesel,
DON'T USE AVTUR! 
It's paraffin / kerosene by another name and you will need a complete fuel system flush (possibly also strip down) if you put it in a PA28. 100LL is, to all intents and purposes, petrol (I know that various things such as lead / water content and other constituents are different to MOGAS) and that's what your donkey needs!
