[Grendel65]

If you live in the USA , its the regulation standards for emission so your ECU will run a slightly richer mixture until the the engine is warmed up which is about when the water temperature is 185-190F. At that point your are back to lowering the emission out the tail pipe and a little less crisp throttle response.

 

[Grendel65]

Yes!
You can get a ECU/EFI Performance calibration that would turn off the radiator fans and go to a aftermarket manual/auto fan control, or readjust there timing sequence, turn off the reporting of the post H02, readjust the fueling timing, knock sensor reporting, delete the mid muffler/resonator, use only 91/95+ octane fuel, readjust the drive-by throttle control, and that just off the top of my mind. hehehehe!

But basically, not really. You couple use the highest octane available (95 preferred) in your area and add a "real" octane booster to increase the octane by a few points? Changing spark plugs can make a notable difference in all aspects of the engine's performance.