Can You Put Car Oil In A Lawnmower? (Plus How To Change The Oil)

When you’re busy keeping your home in tip-top shape, it’s normal to want to find stuff that does double-duty. That’s why we are so adamant about finding homemade tools to clean weighted blankets, remove stains from carpeting, and more. When it comes to lawncare, that double-duty desire keeps going. But, things like putting car oil in a lawnmower can be risky. Is it even doable?

Though it’s possible to use 10W-30 or 10W-40 car motor oil in your lawnmower, it’s not advisable. The best lubricant to use for a lawnmower is SAE 30, which is actually made with smaller engines in mind. To extend the life of your mower, stick to SAE 30 whenever possible. 

Using the wrong type of oil in your lawnmower is a good way to ensure that you have a short-lived mower. At times, it can be downright foolish to use the wrong oil. If you’re new to mower maintenance, we’re here to help you pick the right lubricant for your needs.

Before We Begin: Learning What Oil Is Best

In the world of mower maintenance, there are a lot of different things you need to be aware of. Most mowers tend to abide by the same rules, but it’s always important to double-check. Every mower is different, even when it comes to oil changing techniques and proper oil use. That’s why we strongly suggest you refer to your owner’s manual before you tinker with your mower.

With that said, we’re going to lay out some general guidelines that ring true for the vast majority of mowers:

  • SAE 30 is the optimal oil type for most lawnmowers. This is a type of oil that is high quality and meant for smaller motors. If you want to see if it’s the optimal oil for your mower, check your owner’s manual.
  • Most lawn mowers will be able to handle high-quality car oil as well, but only on occasion. 10W-30 and 10W-40 are the two most common replacement oils for mowers. Using car oil should not be something you do every time, since it can contribute to motor breakdown over time.
  • If you don’t invest in high-quality oil for your car, do not put your car’s oil in your mower. Cars can run fairly well with low to moderately clean oil. Mowers? Not so much. They need to have unusually high-quality oil in order to keep the motors functioning.
  • Remember that extra oil doesn’t improve the quality of the oil in your mower. For some reason, this is a common myth among certain online forums. Too much oil in your lawnmower can do far more harm than good.

How Often Should You Change The Oil In Your Mower?

Your lawnmower needs to be changed about as frequently as your car does, or once every three months. (Note: Do not try to change your mower’s oil every 3,000 miles as this will burn out the engine.) Sometimes, it can be even more frequently, especially if you live in a hot region where oil might “chunk up.”

A good rule of thumb is that you should try to change the oil every 50 hours of runtime. If you notice that your lawnmower has been running rough, chances are that it’s time to change your oil. You would be surprised at how much this can improve your mower’s cutting speed!

Why Does My Lawnmower Need An Oil Change?

Much like with cars, your mower’s motor needs to be lubricated in order to run smoothly. Without having oil, all the gears and belts that make your motor run end up grinding against each other. This leads to engine deterioration, overheating, and overall failure. In other words, your mower motor will burn out much like

How Do You Change The Oil In Your Lawnmower?

Now that we’ve delved deep into your oil needs, it’s time to discuss the elephant in the room: the actual oil changing process. These steps are the general gist for most mowers, but if you want to stay on the safe side, it’s best to follow the instructions in your manual. Here’s what you need to do:

  1. Start by running your mower for two to three minutes before you change the oil. This may seem silly
  2. Remove the gas in your mower. You can do this by removing the gas cap and pouring out the gas. We suggest keeping it in a tub. You don’t always have to do this, but it *is* considered to be good form.
  3. Remove the spark plugs in your mower. This is a must for safety reasons. You don’t want your mower to turn on mid-change!
  4. Grab a pan, and open the oil drain cap. Let the oil drain into the pan, where it can be disposed of safely. If your mower doesn’t have a drain plug, turn the mower on its side (carburetor side up), and empty out the oil from the dipstick hole.
  5. Once you’ve drained out all the oil, replace the oil with a new batch. Use a funnel to pour in the oil to the right tank. If you have an oil drain cap/plug, then replace it and make sure it’s secured in place. Most models will need 20 to 24 ounces of oil.
  6. Add gas to your mower. Put the gasoline in the gas tank, not the oil tank.
  7. Dispose of the used oil properly as soon as you can. It’s worth noting that you cannot just toss out oil into the gutter or the street. Oil is considered to be a toxic waste product and needs to be gotten rid of in a low-risk, appropriate manner.

Please Note: Some lawn mowers also have filters that need to be replaced. If your mower has a filter, make sure to get a filter that is appropriate for your mower and replace it per instructions in your manual. 

How To Get Rid Of Waste Oil

Waste motor oil isn’t just a threat to local wildlife or water systems. It can even be a threat to your local plumbing as well as a major fine to your house. Here’s what you need to know about waste oil disposal.

  • Always check with your state and local offices to find out what disposal services they have. This is the easiest way to ensure that you will be able to find a cheap disposal service in your area. They may also have specific containment guidelines that you need to be aware of.
  • Contain your oil in a polyethylene container or other approved vessel for recycling. When you’re pouring your used oil into a recycling container, make sure that it’s not mixed with other fluids. Mixed motor oil cannot be recycled, and will just turn into toxic trash.
  • Store your oil in a cool, dark, dry area until you’re ready to hand it off to a proper facility. You can choose a state-run service near your local recycling plant, or a facility like AutoZone. (Yes, most major auto supply stores tend to have their own oil recycling programs. Check to see if yours has one before you go!)

How To Make Sure Your Mower Runs Well After An Oil Change

A mower that has a proper oil change will always run better than a mower that is still in need of a change. However, you can always jack up your mower’s performance from good to great with a simple trick. After you’ve wrapped up your oil change procedure, sit the mower upright and run it for two to three minutes.

This might seem pretty excessive, but it has a good rationale behind it. Running your engine will help the new oil soak through your motor. So, this can help improve your overall results. However, it’s important to remember that the actual oil change is the number one most important thing here.

Related Questions

What happens if I put too much oil in the lawnmower?

Lawnmowers that have too much oil will have their sump overflow. This will lead to oil leaks, white smoke pouring out of your muffler, and potential engine damage. If you notice that your motor has been starting with difficulty or if you smell burning oil, you might have put too much oil in your mower.

Can a lawnmower start if it’s low on oil?

Believe it or not, a typical lawn mower’s engine is designed to start, even if it has no oil protecting it from wear and tear.  However, you shouldn’t allow your motor to start when there’s little to no oil just because it can handle it. An engine that’s low on oil will undoubtedly fail, and it will become noticeable when you try to mow your lawn.

Any damage that comes from a mower that runs low on oil is likely to become permanent. As a result of the risk it poses to your mower, some new models have a function that prevents them from turning on if a low oil reading is detected. Unfortunately, this is not a standard feature quite yet.

How long can a lawnmower run without any oil?

Lawnmowers need to have oil in order to continue running. After only one to two minutes of runtime without any oil in its motor, your mower will start to exhibit signs of permanent damage. After around five minutes, you should expect your mower to seize up and be unable to move any further. From here, your mower will be damaged beyond repair and must be replaced.