Q: The airplane owner wants 10% to 20% increase in horsepower without breaking the bank (if that is possible). The engine in the Cessna 182RG is going to be due for a major overhaul in 300 or so hours.
A: Ronnie, I think the best advice I can offer in this case is tell the owner to save his money and look around for a higher horsepower aircraft.
I think if you check the FAA Type Certificate Data Sheet for the Cessna 182RG you’ll learn that this aircraft is probably not certified for a higher horsepower engine.
However, I would also suggest that you review any FAA information regarding any STCs that may have been approved for a higher horsepower engine installation in this particular model of aircraft.