According to JDPower.com, most consumers shop for a lawnmower without doing research first. Instead of determining what kind of lawnmower they need, they base their choice on price. While price is an important consideration, buy the lawnmower suited to your needs, if you want it to last. For example, buy the right size mower, according to the size of your yard. Too small of a machine will wear out quickly.
Even if you choose the right lawnmower to meet your needs, if you don't take proper care of it, it's not going to last very long. A lawnmower needs fresh gasoline, an annual oil change, and spark plug and air filter cleaning/replacement. In addition, the blades must be sharpened -- or replaced if they become damaged -- and the underside must be cleaned of grass and debris. Refer to the owner's manual for specific maintenance instructions.
If you buy a new lawnmower, you can expect it to last an average of seven to 10 years. Used lawnmowers can last just as long, assuming they were taken care of properly by the previous owner, and you continue to provide regular maintenance. Of course, if the lawnmower is already 5-years-old, for example, you can only expect another two to five years of service. Once they reach the end of their expected life, if a major repair is needed, you'll need to decide if it's worth fixing it, or if buying a new lawnmower is a wiser investment.
Don't let the age of your lawnmower determine when it's time to buy a new one. It can last for years -- even decades -- past its average life expectancy. As long as it runs fine, and you can find replacement parts, your lawnmower is fine -- unless, of course, you decide to change the type of lawnmower you have. You may want an electric model instead of a gas-powered one, or decide a self-propelled mower will make life easier, for example. Lawnmowers don't change much from year-to-year. The older models are basically the same as the newer ones.