2005 4.6 - when i fill her up with 91 octane and choose level 3 (i still have canned tunes) is it correct to increase the timing by 1.0? if i increase it more will i get more power. is it safe?

 

No. Level 3 is written for 91 octane, so you make no timing adjustment. It would not be safe. If you fill uo with 93 octane like many of us, then you make the +1.0.

 

ahhh. ok. how did level 3 feel compared to level 2 when you had the canned tunes? i didnt notice much difference but maybe due to the fact that i shouldnt have +1.0 on the timing

 

Mine was very different. Level 2 actually had more power on the low end, since it is for towing, but it faded rapidly after 188 RPMs. Was pretty doggy at highway speeds and for passing. Level 3 is what I used almost exclusively, as I do a lot of freeway and highway driving. Level 3 was not as torquy from a standstill but would pull all the way till I let off. Mush better for passing at highway speeds.