Adjustable mowing height. Some mowers make this easy, changing all wheels with one lever. Look for a mower that offers plenty of mowing height options, from 1 to 3-1/2 inches at least.

Deck materials. Mower decks are traditionally constructed of steel, which is strong, but rust prone. Aluminum decks don't rust but are heavier. Modern plastic resins such as Xenoy are lightweight and nearly indestructible.

Wheel styles. Yes, they're still round, but large rear wheels provide better maneuverability over rough, rocky, or hilly ground. Front wheels on casters instead of fixed in place also improve maneuverability. The best mowers will have ball-bearing wheels. Check to see if the tires have rounded shoulders, which cause less damage to lawns.

Type of engine. Both self-propelled and mulching mowers require more engine power than the old mowers offered. Newer engines are often 6 horsepower. More advanced engines with overhead camshafts (OHC) or valves (OHV) are available on some mowers. These engines are more powerful for their size and they also generate much less air pollution.