Damn, just put the pulley back on, and the chip back in, now I have to go pull everything off again to send the chip out...thanks for the help...sorry about the whole search thing. I was spelling it wrong, so it didn't turn up this most recent thread.

 

Nope the octane number is the same thats the law or your pump couldn't say 93 any more. The winter gas has a higher RVP to help with cold starts. This is the vapor pressure because of more light ends being put into the winter gas. The temp of the air is not what does it, its the density of the air. More O2 and the same amount of fuel.

 

You don't have to pull your pulley off to get your chip reburned. Just drive it with respect for your engine. Stay out of the throttle on the deep end and you'll be fine. I've done it for weeks and havent had any problems except you can't be racing just because someone at the light wants to try you.

 

That's a reliefe...took me an hour to do it yesterday, and I'd hate to think that it was all wasted. I stoped speeding everywhere I go anyways, so driving it nice and slow won't be a problem.

 

Exactly when is cold air NOT denser than hot air. Pretty much NEVER. Technically you are correct but it doesn't change the fact that colder temps make this happen (I'm talking about the air density).

If you are talking about oxygenated fuel adding more oxygen to the combustion mix then that's a different story.