How To Determine The Best Type Of Oil To Use In Your String Trimmer To Clear Out Weeds

String trimmers (or weed eaters, if you prefer) are indispensable tools in the yard, capable of a wide range of tasks from cutting tough weeds down to size to creating razor-sharp garden edges. The engine in a string trimmer often runs at full throttle, so proper lubrication is vital to prevent overheating and a possible seizure. However, using the wrong oil can be disastrous. So, it's a good idea to know how to determine the best type of oil for any machine.

If you check out the best gas-powered string trimmers online or at the store, you'll find there are two engine types: two-stroke (or two-cycle) and four-stroke (or four-cycle). It's an important difference. Two-stroke string trimmers need a gasoline and oil mixture that goes directly in the gas tank, whereas four-stroke motors have a separate oil reservoir, like in your car.

As a result, two-stroke and four-stroke oils are quite different. So the answer to which is the best type of oil to use depends on the string trimmer you own. You shouldn't put four-stroke oil in a two-stroke engine or vice versa, as doing so can risk damage. Your owner's manual almost certainly has a recommendation, although you don't need to stick to a particular brand. You do need to stick to the correct type, and most bottles of oil will clearly indicate what they contain; however, let's look at that in a bit more detail.

Most modern two-stroke engines use a 50:1 ratio: 50 parts gasoline to 1 part oil. The mix is important to provide lubrication without producing excessive smoke and splutter, so do check with the machine's manufacturer. The brand is unimportant. Any two-stroke oil suitable for small engines from a reputable source should be fine.

Four-stroke oils are typically defined by their weight (viscosity), given as an SAE (Society of Automotive Engineers) number. The small motors used in garden equipment, like string trimmers, usually require a lighter oil than that used in vehicle engines. SAE 30 or 10W30 is common, though again, it's important to check the manufacturer's recommendation. Don't assume similar numbers mean the oil is the same. SAE 30 and 10W30 are actually quite different, as their properties change with the climate. And the same applies to two-stroke oils: the brand is not critical, although it's probably safer to buy from a leading brand rather than a lesser-known one.

In both cases, you will have a choice of synthetic or conventional oil. Synthetics offer better protection but are usually more expensive. If the string trimmer is used often and worked hard, choosing synthetic is best. Other maintenance tasks that will help keep your string trimmer running in top condition include checking the filter and spark plug, as well as knowing when to change the string. When storing it for winter, be sure to drain the gas. It can go bad after a few months, so it's best to use fresh fuel to start the machine in the spring.