I use to only run Shell or Exxon gas in my car until about a year ago, when prices went up. The HEB by my house is one of the cheapest in town and really convenient, so I started filling up there. It may be paranoia, but my idle isn't as smooth as it use to be. I don't think that HEB gas is bad. I was thinking that the additives in the other gas stations might have helped keep the engine clean. Should I continue to use HEB and use Seafoam once a year? Or should I go out of my way for a Shell or Chevron gas station?

 

well the heb by my house, actualy gets the same gas the shell station gets. so if you can just try and find out what gas they recieve?