I know this question may seem pointless but I think it's necessary in our world of rising gas prices. What kind of rwhp/rwtq can a bolt-on (CAI, headers, catback) 5.3 get with an "aggressive" 87 octane tune? Is it even possible to create an "aggressive" 87 tune with no hint of KR or detonation? Any info would be appreciated.

 

Not likely to really get "aggressive" since I would bet a scan would reveal some KR with a stock tune on most vehicles. As far as the rising prices go, the gap between the octanes is staying the same so realatively speaking the total cost gap from low to high octane is shrinking. In other words your not really saving as much as you think using 87 octane.

 

On my truck I get more MPG out of my 93 tune than my 87 tune, so that makes it a no brainer when you factor in the perfromance.

 

im running an 87 tune and i have added a bit of timing and have 0 KR. no dyno numbers though. butt meter says its running lots better though.

 

The difference in a full tank is about $5. Just do the tune for the highest octane available

You also get the benefit of the better additives with premium.

 

Thanks for all the inputs. You all made some good points. I think I'll stick with a 93 octane tune instead.

 

it only costs me like $4 more a tank to fil up with 91 instead of 87....i'd stick with 91

 

That's why PCM's have high and low octane tables. Tune your high octane table to 93 and your low octane table to 87. I don't know the exact details, but the PCM should take care of the rest.