For flat spaces, low horsepower mowers like those with 15 hp would do the job just fine. If you have uneven ground with a couple of slopes, look for a more powerful mower with 18 to 24 hp. Steep ...

So if you don't mow as often, you'll need more oomph to get through such dense lawn, and an engine with higher horsepower of at least 19 hp can handle that for you. Horsepower also matters once ...