How to Change Lawn Mower Oil (and How Often), According to an Expert at John Deere

There’s nothing quite like the instant gratification that comes from a freshly cut yard. But if you’re neglecting the regular maintenance of your lawn mower, this lack of attention will eventually catch up to your grass. Just like the engine in your car needs its oil changed regularly, so does this small engine that serves as the foundation of all other lawn upkeep.

Luckily, our experts are here to walk you through the process of how to change the oil in your lawn mower without damaging your machine—along with other best practices to consider.  

Why It's Important to Change Your Lawnmower’s Oil

Oil is what powers your lawnmower’s engine, says Eric Halfman, go-to-market manager of riding lawn equipment and gator utility vehicles at John Deere.

“If the oil levels get too low, it can seriously affect your mower’s performance and even damage the engine,” Halfman warns. “Regular scheduled maintenance, such as oil changes, help your mower start quickly and run more efficiently.”

Consider Biodegradable

Until recently, most small engine lubricants have been petroleum-based, explains Arie Brish, best-selling author, entrepreneur, former Fortune 500 executive, and business professor at St. Edward's University in Austin, Texas

But these are bad for both the environment and the person operating the machines. “Governments have done decent jobs regulating the pollution from automobiles, but totally neglected the small instruments,” he says.

However, one emerging trend in small engine use is to use biodegradable lubricants. “These are better for the soil when dripped—and better for your lungs when you breathe the lawnmower fumes,” Brish says. “You may want to consider using biodegradable lubricants rather than petroleum-based lubricants the next time you change your lawn mower’s oil.”

Signs Your Lawnmower's Oil Needs to Be Changed

“You can tell if your lawnmower may need its oil changed by checking the oil level before each use and comparing it to the levels indicated in your owner’s manual,” Halfman says. “John Deere recommends changing your oil at least once per season, or after about 50 hours of use.”

How to Change Oil in a Lawn Mower

Halfman offers the following directions to properly change the oil in your lawn mower.

Materials Needed:

• Oil drain pan
• Old towels
• Leak-proof container to store/transport old oil
• Funnel
• New oil (based on the type your specific manual recommends)
• New oil filter
• Protective eyewear
• Heavy-duty gloves

Step-by-Step Instructions:

1. Gather Tools and Safety Gear: Make sure you have all supplies on hand before you begin. 
2. Warm Up the Engine: Run the engine for one to two minutes, which will help the oil drain more easily. Then turn it back off. 
3. Drain the Old Oil: Ensure the mower is on a flat surface, then place the oil pan under the drain valve. Next, carefully open the valve and let the oil drain completely. Be careful during this step as the oil may be very hot. Once drained, close the valve and wipe away any excess oil. 
4. Remove the Old Oil Filter. Move the pan under the oil filter, then remove it by unscrewing the filter counterclockwise. You can then dispose of the filter and old oil—but never pour oil down the drain or throw it in the trash. 
5. Install the New Filter and Add Oil. Install the new oil filter, tightening it gently, but be sure not to over-tighten. Use a funnel to add new oil according to your mower’s manual. Before checking the oil level, secure the dipstick and run the engine briefly to pump oil into the new filter. 
6. Perform Some Final Checks: Inspect the filter and drain valve for leaks. Finally, check the oil level with the dipstick and top off if needed (but avoid overfilling).

How to Dispose of Used Oil

Never just toss the old oil in the trash or down the drain. Instead, check with local auto supply stores or nearby recycling centers to see if they accept used oil and, if so, what are the specific requirements. Be sure not to mix it with other liquids like antifreeze, brake fluid, or even water.

When to Seek Help

If you're uncomfortable changing the oil in your lawn mower or performing other regular maintenance, you can always reach out to your local dealership or small engine repair shop.

Trained technicians can provide help or recommendations, and it’s always best to get an expert’s advice if you feel out of your element.