Get yourself a knocklink and you'll be able to keep an eye on detonation, if you get a bad batch of fuel, then you'll know as it will flash warning lights at you.
Thanks folks I dont think Maxol would tell people that all their unleaded was E5 if its not but I really dont want to damage my engine and Idid speak to one of their sales managers and he confirmed that all their unleaded was E5 CHEERS.