When and How to Change Oil in a Lawn Mower

The Family Handyman automotive expert, Rick Muscoplat, will show you how to change lawn mower oil.

checking oil on a lawn mowerrookman/Getty Images

It is important to change the oil in your lawn mower to make sure you are getting the best performance along with preserving the lifespan of the small engine. Follow our guide from the experts on when and how to change the oil in your mower.

When to Change Oil In Your Mower

Depending on what type of lawn mower you are using, here are the recommendations on when to change or add fresh oil to the mower.

  • If it’s a new mower engine, you typically want to change and replace the oil soon after its first use. That generally clocks in at roughly five hours of run time.
  • For existing push mowers, like shown in the video below, its recommended to change and replace the oil at least once a season or for every 50 hours of run time.
  • For existing riding mowers, it is recommended to change and replace the oil at least once a season, or for every 100 hours of run time. This can be done as part of your regular repairs and maintenance.
  • Consideration: It is valuable to check the oil before each use, as strenuous conditions such as hot or cold weather, wetness, dust or forceful use could increase how often you should change the oil.

Some people like to change their lawn mower at the end of the season, as part of the lawn mower winterization process.

How to Change Oil in a Push Mower

Changing your oil for a lawn mower after every 25-50 hours of use will keep your engine healthy. Find out the best way to change oil for a push lawn mower in this video.

  1. Seal the gas tank: Seal the gas tank by removing the gas cap and covering the opening with a plastic bag. Screw the cap back on over the plastic bag.
  2. Empty out the old oil: Remove the dipstick from the oil filler tube and tip the mower to drain the oil. Pour the used oil into a plastic milk jug or similar container and recycle it.
  3. Refill with clean oil: Refill the engine with clean oil. Most engines require about 20 ozs. (5/8 quart). Insert the dipstick and check the oil level. Add oil if needed but don’t overfill.
  4. Alternate oil draining method: Unscrew the plug located on the bottom of the engine and allow the oil to drain into a pan. Lower the mower down on its wheels to make sure all the oil drains. Replace the plug. Then, set the mower on a level surface and fill the engine with clean oil through the filler hole near the base of the engine.

How to Change Oil in a Riding Lawn Mower or Zero Turn Mower.

Follow the same general steps as you would a push mower. Refer to your owner’s manual or online tutorials for the location of the necessary parts to complete the job.

Lawn Mower Maintenance

Using the right type of oil is important to getting the best performance from your engine, so make sure you know what type of oil is best for your lawn mower. To make sure that your lawn mower and engine is performing at its best, make sure you know how to do a lawn mower tune-up to maintain and repair your cutter.