There is a trend by the sales people to specify small engines used on yard equipment in cubic centimeters.The public has been exposed to horsepower, since day one and usually understand what size engine is required to operate the equipment under normal conditions. CC's and Horsepower are like apples and oranges. CC's are a unit of volume and horsepower is a calculation of work load. You can''t calculate the horsepower, only measure it. Here is the CC to HP ratios of some engines 40, 36, 9.2, 9.6, 24. This is to point out the fallacy by some to associate so many cc be equal to a specified horsepower. There is absolutely no realistic relationship between cubic centimeter and horsepower. Both have their uses but have completely different purposes. Cubic centimeters (cc) for a road vehicle is fine. A smaller cubic centimeter engine will not have the same acceleration as a larger cubic centimeter engine on identical sized vehicles. Both will function adequately to maintain a suitable road speed. Now let us look at say a rototiller or snow blower. Within minutes of use due to different conditions encountered, various degrees of power will be required to have adequate operation. A 3.5 Horsepower (HP) device will be straining, whereas a 8.5 HP unit may operate without a difficulty, under the same conditions of operation. Since HP is measured when the engine is in perfect condition, this unit has significant meaning to a buyer, and can be used as a guide as to what size to purchase for any given application. I suggest the manufacturers and sales people are trying to obscure inferior equipment by utilizing cubic centimeters. Yesterday I was looking at snow blowers, and found the same physical size machines in different stores one at 200cc and the other at 300cc. No mention of horsepower. Having had a snow blower in the past, I know that 10 HP can handle the typical heavy snow storm without difficulty. But a 300 cc and 200 cc unit indicate absolutely nothing useful, uninformative claptrap, since the relationship to HP has no meaning. Horsepower is meaningful and cc is obscure nonsense. Further to relate cc to HP indicates that the person doing so is not knowledgeable. It is time us consumers started a campaign to get the manufacturers and sales people back on track.