By Benjamin Gracias May 12, 2026 9:25 pm EST
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The engine's longevity depends on what's going on inside the lawn mower. The biggest differentiator is the lubrication system. Cheap, entry-level engines often use splash lubrication, where a little plastic flinger or a dipper on the connecting rod splashes oil around the crankcase. It is a cheap and simple system, but not an efficient one, especially if you are mowing on a slope where the oil pools to one side, leaving the other dry. Premium engines utilize full-pressure lubrication. These systems have an actual oil pump and oil filter, just like your car. These ensure that critical parts of your engine, like the main bearing, remain lubricated by pressurized oil.
Then there is the cooling. Most lawn mowers are air-cooled, relying on fins and a flywheel fan to shed heat. If those fins get clogged with dried grass clippings, the engine temperature skyrockets, thinning the oil and damaging the seals. Liquid-cooled engines are more expensive but provide a much more stable operating environment, resulting in a lifespan superior to that of an air-cooled engine. Electric lawn mowers have none of these problems, which is good news considering companies like Home Depot want to phase out gas-powered lawn equipment. However, compared to gas or diesel mowers, electric lawn mowers have a shorter lifespan, mainly due to their batteries.
Extending your lawn mower's liefspan
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If you want your lawn mower to become a family heirloom, you have to treat it like a machine, not an appliance. A bit of regular maintenance goes a long way. While basic lawn mower checks are a good place to start, here are a few tips to keep your lawn mower running well for a long time.
Change the oil religiously. Small lawn mower engines do not have massive oil capacities like your truck. The manufacturer-recommended oil change interval is typically 50 hours or once a season, whichever comes first. Fresh oil isn't just about lubrication — it's also about removing contaminants and debris. If your mower has an oil filter, change it along with your oil.
Modern ethanol-blended gasoline is hard on small engines. Ethanol attracts water and, over time, turns into a corrosive gum that damages carburetors and fuel lines. Use ethanol-free fuel if you can find it. If you can't, use a fuel stabilizer, especially before you tuck the mower away for the winter. If your air filter is choked with dust and debris, the engine runs rich, leading to carbon buildup on the valves and spark plugs. Check and clean the air filter after every 25 to 50 hours. If it's paper, replace it. If it's foam, wash it in soapy water and let it dry.
Sharpen your blades. A dull blade forces the engine to work harder to cut the same amount of grass. This puts unnecessary stress on the crankshaft and increases the operating temperature. These maintenance tips should do the trick, unless you end up owning one of those crazy Kiwi racing lawn mowers.