Or the more bureaucratic approach: "Ask your mother first."

 

I think once I get the tuner/CAI combo from Americsn Muscle I am going to put an 89 race tune on it.

 

Wrong, unless you get an economy tune which is basis for having your man-card taken away.

A good tune will increase performance and NOT reduce fuel mileage unless you're really putting your foot into it. Very, very few people report better gas mileage and I'll put money on the fact that they make that statement based on a very limited # of before and after data and without consideration of all the variables that readily skew that data.

But as far as the OP's original question which I may have already answered above, there have been very rare occurences where someone has bricked their PCM by doing something wrong. However, many folks will change tunes frequently (for awhile I was experimenting between my 3 custom tunes and was changing tunes 3 - 6 times per day over a 1 week period) and don't think twice about harming the PCM.
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I'm sorry, your mistaken. Neither of us work as engineers at SCT but Justin at VMP did. E-mail him and ask him. I have 3 tunes like everyone else. Mine created from the dyno at Excessive Motorsports. One of which, is an 87 tune for fuel economy. Bypassing Fords restrictive parameters can easily give you alot better gas mileage. Fact. I occasionally drive to D.C. daily which is 102 miles round trip. Working for a living while driving a Mustang to work does nothing to take my man card away.

 

I do like my tunes but I do not get better mpg. I lose about 2 mpg both in town or on the highway. Even crusing steady I am down about 2. However I don`t mind it a bit. I didn`t get the car for it`s mpg.

 

1) Not gonna lie, I went from 12 mpg to 14 mpg average after the tune and CAI...

2) My dad gave me crap about it at first, but now he wants to get a tuner and CAI for hit R/T Charger. haha

 

HAH HAH, Nice!

 

The tune was either from a company that didn't know what it was doing or it was a resistor type "chip" that are sold all over flea-bay for like $20-$50. Those are NOT tuners, those are resistors made to fool the engine into leaning out your mixture and those WILL cause damage.

Stick to a reputable tuner like Brenspeed, American Muscle, Lund, etc and you will be fine.

Anyways, who pays the bills for the car? if you do, then it's you responsibility. If your dad does then help him change his mind.