That second is an interesting ad.
260 is, or also is, a racing fuel.
Lets see what's currently offered.
Yup 260GT and GT plus have eth (oxygenated) and GTX is non-oxygenated. Sunoco Race Fuels
And you used to be able to get it at the pump back in the day. Still can at select stations around here. There is one over by Glen Mills that still offers it at the pump...pricey though.