Originally Posted by Jeff d
It says 93 Research Octane (RON) though. RON is more common worldwide but gas pumps in the US are labeled with (R+M)/S (AKA Anti Knock Index). 93 RON = 88 (R+M)/S. Look at the buttons on the pump next time you get gas. They will say (R+M)/S in the fine print under the "87", "89", etc. So, 93 RON = "Regular Unleaded" in most US regions.
Yep, there is no reason to waste money on 93 when clearly it will run on 87. I would be more concerned about the valve seats and running unleaded fuels.
Here is a link to a nice RON/MON conversion.
With this you can see that a 93 RON is close to 86 or 87 so using regular 87 is going to just fine. Once again, lead seems to a bigger concern unless hardened seats have been installed.