Tuning your engine to require higher octane gasoline?

I am most probably to get a 2004 great Prix with a 3800 series III engine 200 HP and 230 ft lbs torque . The car performs great already, but I had heard that having your car tuned to require a higher octane level, you may be able to increase your hp.

I'm to get a great deal on the car, otherwise I may think about the GTP variant. But I am inquisitive, how many more horses can I squeeze out of the engine by tuning it for higher octane gas. I am aware that some parts may have to be exchanged.

How much could it cost? How could it influence my fuel economy?

use up the money to learn to be a better driver

lots of HP in a poor drivers hands=disaster

the simplest way is to just purchase the supercharged variant of the great prix and be done with it.

Shouldn't have to do anything specal to your car to use a higher octain fuel. Unless you're upgrading the moter and everything else for the higher horse power.

I am not sure who in particular is making tuning software for your particular application. You may attempt Superchip, max systems or a alike company.
Most of the "hot" tuners are working with forced inducted engines, i.e. turbo charged, supercharged or blower driven vehicles. In these applications the tuner can make small alterations with high yields in change. This is done by rising the amount of increase the turbo or supercharger supplies to the engine. When you increase increase you increase the amount of air going into the combustion chamber, add to that extra gas by "tuning" the fuel injection computer scale, level or density. By rising air volume and fuel into the cylinder you effectively change the "VE" or volumetric efficiency.
Simply stated the higher the VE the bigger the engine effectively is. This is why a little turbocharged four cylinder can create well over 300hp, or as much if not more than a V8.

Since your car is conventionally aspirated, not forced inducted, the "tuning" only changes are a more restricted. based on what is available for your engine is can be as simple as a chip flash or handheld programmer with restricted alternatives.
The reason many of these upgrades require premium fuel is that they change the timing and fuel mixture, these modifications with the addition of a better flowing air cleaner system and a cat back exhaust you could look at 15 20hp get. But the wrong exhaust could cost you to lose torque.
The racers adage is simple. Speed is money, how fast do you want to go?
Cost A pre packaged programming chip 175 500.00
High flow cold air syst. 100.00 500.00
Cat back exhaust 200 2000.00
Add .20 cents per gallon for premium gas.
How much is an 20hp worth?