Weird thing happened when I first got my truck.  After the full tank provided by the dealer,which was super, I put in normal 87.  I thought the truck felt less 'peppy' because throttle response seemed to really drop off. Then, right at half a tank, my check engine light came on.  Stunned, I contacted my dealer and they asked what fuel I was using. They then said they would not recommend using it.  I took the truck in, and they reprogrammed the control unit, which took about an hour.  I have run Super in it ever since. I always put Super in my Porsche's, boat etc, however I have always used reg unl in my trucks.  It may be a glitch in the fuel system ECU but it sounds like many here run regular.  Do you think changing from one fuel grade to another could do it?

 I have been buying Super here in New Orleans for a 1.99 so it's not as bad as many other places, however I would prefer to run regular in it.