Sunoco at some stations sells/sold cam2 Cam 2 available in 110, 112, and 116 octane leaded. When gas was around $1.00-$1.50 a gallon it was around $3.50 at the one my town had. They do not use lead(tetraethyl) in their unleaded gasoline which should go without saying. Though it appears not. Sunoco had used mmt which was originally used in leaded gas as an anti-knock though it was then used in unleaded as well. Lead also helped with valve seats and wear. Which is why many engines when rebuilt use hardened valve seats to run unleaded.