Familiar Horsepower Rating No Longer Standard

By Rick Barrett
Milwaukee Journal Sentinel
Saturday, February 16, 2008

For buyers of lawn and garden equipment this spring, a familiar old term -- horsepower -- will be missing from many engines.

Blame it on lawyers, or on engine makers who might have fudged the numbers, but horsepower is no longer the gold standard for small gasoline engines.

Sears, for example, now advertises some lawn mowers rated by horsepower, others by torque and still others by cubic centimeters. Some mowers have no designation at all.

"Unfortunately, we are not giving consumers the answers they want," said Bill Rotter, a Milwaukee-area hardware store owner.


In basic terms, torque is a measure of the force needed to turn something, like a wrench or a lawn mower blade.

"We think it's a better measurement of a mower's ability to cut grass," said Rick Zeckmeister, North American consumer marketing director at Briggs, the world's largest manufacturer of small gasoline engines.

Horsepower, on the other hand, evolved from a measure of the rate at which a horse could pull coal up a mineshaft into a more technical measurement related to watts. Although most people don't know its technical meaning, many have found horsepower useful in comparing the power of engines.

So now consumers may face confusion over how torque relates to horsepower. There isn't a practical conversion chart because torque and horsepower measure two things.



The shift away from horsepower ratings came after a lawsuit in Illinois claiming that engine manufacturers were overstating the horsepower of lawn mower engines.

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