Anyone who pumps Sunoco into their vehicles is putting 10% ethanol in their tank.  I use Sunoco often in my vette and never thought twice about the issues with ethanol.  Methinks I'll switch to another brand...

I have my 70 vette 454 in Colombia South America, here all gasoline is biogasoline ( mix 85% gasoline and 15% ethanol). This is the worst thing you can put in a carburated engine. It ruins rubber hoses, tank and fuel line rust problems; but the big headache is that it causes vapor lock in fuel pumps. On hot days or climbing mountain roads, fuel boils and electric and mechanical fuel pumps go crazy. Very few places in the country have unmixed gasoline (ethanol free) and there is no problem.