badogg

Hey everyone, I'm new here.

I just installed a JLTII+SCT3 from Brenspeed this weekend and had a couple of things that I was curious about. So I thought you all might be able to help.

1) Changing octane - So I loaded an 87 octane tune as that was the gas that was in it. When I am ready to load up a 91 octane tune, is this something that I need to do at the gas station at the time of fill up? Or is it ok to drive the car with 91 octane fuel but with a 87 tune?

2) For the SCT3 tuner, I see that I can upload the stock tune strategy back to the car and that when I do that it apparently can be used with a different vehicle. I also have a 2003 F150, so I was curious if could load the stock tune to the mustang, then load a SCT standard tune to the truck when we need to take the truck on a trip, then when we get back put the truck back to stock and then load the custom tunes from Brenspeed back to the stang. What do you guys think?

Thanks again...

Nuke

Hi and welcome to the forum.

Regarding item #1, you can safely run any tune providing the octane value is equal to OR HIGHER than what the tune calls for (although you won't benefit from the higher octane on the lower tune). Best bet for a higher octane tune is to fill-up with the higher octane first, run that tank and refill again before loading the tune for that octane. There ARE ways around it such as adding a half tank of 91 to a half tank of 87 and loading an 89 tune for instance, if you want to do the math using ratios.

I can't speak on #2 as I've never used my tuner for another vehicle.

shanec

When I switched to a 93 tune, I ran my 87 tank down as close to empty as I could. Then filled up with 93, loaded the tune, and took off. After 1-2 seconds of engine pinging, I realized the 87 still in the fuel lines still needed to run its course, so I took it easy on the throttle for the next 5-10 minutes then all was good.

shoeys08dkcandygt

+1 on what shanec said. and you cant use the tuner for 2 diff vehicles at once. they have diff pcm codes.

brunobluto

you can use the tuner on your truck once the stock tune is uploaded back in your car. i'm not sure about your particular tuner, but some will only allow you to switch back and forth between vehicles 5 or 6 times. when you switch between vehicles, the tuner should let you know. iv'e done it with my 05 gt and a ford 7.3 diesel, forget what year, maybe 2002?