What will happen if I use 87octane

Discussion in 'SVT Tech Forum' started by rdefino, Aug 12, 2004.

  1. I went to fill up the other day and put in 9 gallons of 87 in my 03 Cobra before I realised. I switched at that point. I started out with a 1/4 of a tank. What will happen to the car?

  2. Knock sensor should retard timing if there is an octane issue. Just don't whale on it.
  3. You'll probably be fine, but be careful if you drive it WOT because you might get some detonation. I'd throw in a bottle of octane booster just for insurance.
  4. I would just drive it a while and keep topping it off to keep diluting the 87 octane. Should not be a big issue though. Like above said, stay out of the rpms and since you got an 03 the boost too ;)
  5. octane booster=smart idea....
  6. get to about half tank and then refill with some CAM2 or Sunoco 100...run that dry refill with usual and youll be good :nice:
  7. dont listen to that last guy, cam2 will clog your O2 sensors and I doubt you want to shell out the money for that.
  8. Eh, just don't stomp on the engine. No WOT runs in the meantime...you don't need to add anything to your tank.

    Why make mountains out of molehills people (spending lots of unnecessary $$$ on fuel additives, you're just throwing money away :doh: ). :shrug:

    Ford engineers thought that someone would probably refuel with sub-premium fuel on accident, so the PCM/knock sensor will do it's job.

    Just remember to put premium in it next time & drive like a grandma until you refuel again... :D

  9. 03/04 Cobra's DO NOT have knock sensors! The SC makes too much noise so Ford didn't equip the new snakes with them.

    Drive it around and stay completely out of boost until you've burned off enough to top it off with some 91 or higher again. As long as you're not flogging it and putting a heavy load on it you'll be okay. Don't bother putting ANY off-the-shelf octane booster in your car either, it would take 20 bottles just to raise the octane rating a whole point! Octane booster is a COMPLETE WASTE OF MONEY!