is there a Cold Air Intake and tune that makes reasonable performance improvements, BUT will allow you to use regular gas?
Or will I have to use Premium / high octane? My Mustang is an auto/'vert and is a cruiser, but I sure would like a little better throttle response and shift action. I'm an old Mustang guy brought up on carburetors & dual points, so FI and fuel management computers are all new to me. Thanks for your help...

 

Most intake/tune packages come with an 87 tune. There you go.

 

Yup,

I'm running a C&L with Brenspeed 87 tune and it's a huge improvement from stock.

Where I am, it's 0.20 per gallon more for high octane, translating to between 2 and 3 dollars per
average fillup, so I just loaded with 93 and once I get the rest of the 87 out of her, I'm going
to try the 93 tune.

 

do you specify "87 tune" or do you get an assortment of tune programs included in a kit?
Ford Racing is a safe bet I guess, any suggestions for what brand to buy?

 

If you go brenspeed you will get an 87,91, and 93 octane tune. You can special request other octanes in place of one of the 3 if you want.

I got the JLT2/SCTII package and have been pretty happy with it.

 

Just about all of the vendors (Brenspeed, Bama, VMP) will provide you 3 tunes with the tuner. The 87 tune is hands-down way better than the stock 87 tune. Matter of fact, there's a bigger difference between stock 87 and custom 87 tune then there is frombetween thecustom 87 to custom 93 tune. Go for it.

 

I went with Brenspeed....got the SCT X3 with the 3 tunes mentioned above. I loaded the 93 tune and haven't looked back. BTW, I am running an AirRaid CAI and have had no problems there either....I have no experience with any other CAI on this car though.

 

M5 3.55
Stock 17/27 mpg.
JLTII CAI and Bama 87 Perf Tune 18/28 mpg
JLTII CAI and Bama 93 Race Tune 19/29 mpg

In my experience the 93 octane tune comes close to paying for itself.

Add an Spydershaft and 4.10's and get 21/27 mpg.
Since 70% of my driving is in town Im happy.

 

Thanks everyone this makes sense and is good advice.

 

I've got a question to add to this since the OP got his answer. Do any of you notice a huge difference between your brenspeed 87 tune and 93 tune?