Odd question...I bought my car with a CAI, exhaust, and tune installed. I'm assuming it has a tune because of the CAI, and it also had the SCT emblem stuck on the dashboard. Anyway, the problem is I don't know what type of tune it has I've tried 87, 89, and 93 octane to try to figure it out by feel, but they all feel similar, obviously 93 gets better gas mileage and feels a bit smoother, but that's to be expected. Is there an easy way to figure out what kind of tune my car has?

 

if you can't get the car to ping under heavy load using any of the octanes, i would say if there really is a non stock tune in there, it would probably be an 87 tune.

 

What type of CAI is it? Some CAI's require a tune and others do not. Typical situation, the old owner of the Stang would change the car back to stock and keep the SCT tuner for their new car. I am assuming, since you did not get the SCT tuner, the car is set back to stock, therefore, the octane needed would be 87.
Is your car throwing any codes?

 

It's a K&N intake...I was under the impression that it required a tune. Not throwing any codes at all and the engine doesn't ping with any of the 3 types of gas.

I plan on installing my own tune anyway, so it's not a huge deal.

 

Assuming it does have an 87 tune, putting 93 in it will not affect anything, correct? I'm a tuning n00b.

 

No worries. ;-)

Yes, that is correct. If you have a 87 tune, you can use 87 and higher octane and will not cause any issues.

The octane needs to be equal or higher than the tune. For example, if you have an 87 tune, you can use 87, 89, 91, 93 octane. However, if you have a 89 tune, you can use 89 and higher octane. If you have a 93 tune, you can only use 93 octane or higher.