How to know when a custom tune is needed?

[chopper_man]

Hey all,
Rookie here! My U7140 Predator should be here tommorow. Looking forward to it! Anyways, got an 06 Mustang V6 5speed with a Roush CAI, Husrt short throw and single GT take-off exhaust. Are the standard 87, 91, 93 tunes enough? How do you know when a "custom" is needed? Everything I read says heavily customized. I'm no where near that, but will a custom get me anything more than the included tunes? I'm primarily looking for overall improvement and MPG gains.
Thanks!
-Brian

[christina]

There are CAI tunes in the Predator (Roush is the same as AirRaid). Exhaust and small mods can be done without any custom tuning but once you get into longtubes, heads, etc. a custom tune is needed.

[chopper_man]

Hi Christina,
I cant seem to find whereto do that! I just did the latest software for it as well (8r38). When I plug it in I choose Performance Tune then I get the following options:
87 Octane Performance
91 Octane Perrformance
93 Octane Performance
C&L Street Kit
JTL Induction
91 Octane Steeda
Modify Stock Tune
Original Backup

[christina]

Ah I must have missed the v6 part, apologies. Try installing the correct octane tune and add 5% to the MAF curve in the parameters.