Why did you let her take the truck?

 

j/k, Good luck and let us know what you end up doing to her (not the wife )

 

Agree..I live in the boonies and occassionally have to put in 87 octane (SC 91 Tune) to get me to the big City (40 Thousand People) like say 10-15 bucks worth, but also add appl. ratio of Penzoil Octane booster at the same time as I always carry a few for that purpose. I realize that the booster probably only boosts it to 89 if I'm luckey as the 3 point boost claimed on the can is questionable. I have never had any problems or knocking in these situations, but ensure I fill with 91 as soon as I get to town. If its a full tank of 87 you got, I would re-tune to 87 and add an octane booster.

 

Yep, the timing is advance quite a bit with the performance tune and as a result, even if you don't hear it, you can bet there is a fair amount of predetonation going on.

The 87 octane tune is still a better performing tune than stock, so I'd run it on that until you get the tank at least down to about a quarter tank. If you can get 3/4 of a tank of 93 octane in it, then you'd prolly be at or close enough to the 91 octane for your performance tune.

Also, I hope you are switching to the tow tune when pulling your trailer, pulling over 2k pounds is a no-no with the performance tune...

 

it wont do anything.... i have the 91 setting on mine and i run 87 all the time. I have not felt any difference at all--- even with fuel milage. I live in alberta canada so i dont know if our gas is different then the states.
I think its been a few months since i put 91 in. I use a Lucas fuel additive thought and i seem to get a little better milage with that.