Yeah thats right Steve, and the lead in leaded actually boosted the octane level to 96RON
Meanwhile unleaded is 92RON, 4 points below (Incase u r bad at maths!)
LRP (Lead Replacement Petrol) has tin instead of lead in it. It doesnt have the same properties as good old lead, but they boost the fuel upto the 96RON.
With Premium unleaded, its 95RON, so add a valve lube to the fuel and like magic u can run ya old banga on it. Who knows, it might even run a little smoother than on LRP?!!?