Going to high in octane "usually" does NOT hurt anything. I guess you can argue it burns hotter and might throw something off, but I doubt 97 Octane will do that.
Its more a waste of money if anything, since it doesn't get you anything.
Higher octane doesn't atomize/vaporize as well, so using a higher than recommended octane is often a cause for poor starting and cold running in cold weather. It can also reduce mileage a bit.
This is what my Owners Manual (2010) has to say on the subject.
Materials Added To Fuel
All gasoline sold in the United States is required to
contain effective detergent additives. Use of additional
detergents or other additives is not needed under normal
conditions and would result in additional cost. Therefore,
you should not have to add anything to the fuel.
Fuel System Cautions
Follow these guidelines to maintain your vehicle’s
• The use of leaded gas is prohibited by Federal law.
Using leaded gasoline can impair engine performance
and damage the emission control system.
• An out-of-tune engine, or certain fuel or ignition
malfunctions, can cause the catalytic converter to
overheat. If you notice a pungent burning odor or
some light smoke, your engine may be out of tune or
malfunctioning and may require immediate service.
Contact your authorized dealer for service assistance.
• The use of fuel additives which are now being sold as
octane enhancers is not recommended. Most of these
products contain high concentrations of Methanol.
Fuel system damage or vehicle performance problems
resulting from the use of such fuels or additives is not
the responsibility of the manufacturer.
NOTE: Intentional tampering with emissions control
systems can result in civil penalties being assessed
Methanol is corrosive to a lot of seals and even some metals used in a lot of fuel systems.
Seems like the standard OEM warning against the aftermarket additives industry, which most are a rip-off, if they do anything at all, besides lighten your wallet, they do more harm than good.
Thats NOT all additives, some are quality; but I agree with the advice, in most cases people over use additives NOT realizing that most of the quality fluids they buy already have additives doing exactly what they are looking for additional additives that do NOT do as good of a job as the original fluid does already.