Okay i have the x3 tuner. And i have a custom tune on it. Whenever i plug it into my car to upload the tune I can edit saved options>then it has thing like air/fuel ratio,speed limiter,shift pressure. Say I take off the speed limiter, and put my shift pressure up. Does this reset my tune or just add to it?..

 

Also the reason I was wondering is because all of the options are at zero when I go to saved options. So i dont want to change like the speed limiter and and save it and all the other options get saved to.

 

only changes will be saved. it will say 0 but say yourspark advanceis 18. If you add 1 then it will go into your car as 19.

 

Those are adjustments ontop of what your tuner has already done.

 

I say don't mess with it if you don't know what your doing. You bought a tune for a reason. If you need to make changes, I'd go back to your tuner and have them do it (except for things like gears/tire changes).