That depends on the type of tune you uplpoad. For example, I have three tunes in my SCT handheld tuner...93 octane, 91 octane and 87 octane. So, if you load a 93 octane, you obviously have to switch your gas to match the octane. Here's another side of this: You could upload a 91 octane tune and use 93 octane gas...BUT it;s not recommended you do it the other way around. Meaning, upload a 93 Octane tune and use 91 octane gas.
El Boricua. Roush Fascia/chin/scoop, DD 18X9 w/NT555 255/45/18, GTA Axlebacks, GT500 spoiler/pedals. Interior billet upgrades, seq lights, eng dress up, chrm valve cvrs, BBK Shorties, Steeda LCA, GMS CAI SCT X3, Brenspeed 93 Oct tune, drilled/slotted rotors.