Can You Use Car Oil In A Lawn Mower?

Most lawn mowers are powered by internal combustion engines, which could be one of two types — two-stroke engines or four-stroke engines. Similar to cars, lawn mower engines have many moving parts that work collectively at extremely high speeds and temperatures. 

These parts need to be lubricated with oil to run smoothly, without which your lawnmower overheat, seize or get damaged. But what if you run out of lawnmower oil, but do have a few bottles of car oil stacked in your garage? Is lawn mower oil the same as car oil?

Can you use car oil in a lawnmower? Yes, you can and most will work just fine with SAE 30 oil.

But if you just want a quick recommendation or your lawnmower, you can’t go wrong with the Briggs & Stratton 2-cycle oil. Have Amazon send it to you…

Briggs & Stratton 2-Cycle Easy Mix Motor Oil - 16 Oz. 100036
4,820 Reviews
Briggs & Stratton 2-Cycle Easy Mix Motor Oil - 16 Oz. 100036
  • 2-cycle easy mix motor oil
  • Fuel stabilizer that leaves no residue and prevents plug fouling
  • Recommended for toro, lawn boy, ryan and other 2-cycle outdoor power equipment

Can a Lawn Mower Run Without Oil? 

This depends on the type of lawnmower you have, where some newer models will not start without oil, and other standard mowers will start, but will not run for a long time. When this happens, your lawnmower is most likely to emit a knocking sound from the engine immediately after startup. 

Some lawn mowers are fitted with a low oil switch, which is designed to monitor the pressure inside the engine, and shut it down if it falls below a pre-configured level. Even if your lawnmower is equipped with a low oil switch that will engage if the machine runs low on oil, it is best not to wait until the last minute to top up the oil. 

But just like cars, it’s highly recommended that you do not wait for the low oil indicator to turn on, but replenish your lawnmower with oil regularly to ensure all the parts are well-lubricated at all times. The easiest way to check how much oil is in your lawnmower is with a dipstick which is usually part of the mower. 

Some gardeners inadvertently put too little or too much oil in their lawnmowers, which causes the engine to seize or smoke when started. Although smoke issues can be fixed, any repairs with regards to the engine, whether cars or lawn movers can burn a hole in your pockets. 

Tip Mower on its side to drain oil

If you notice, you’ve got too much oil in your lawnmower, simply tip the machine over slightly to let the excess flow out on the other side of the air filter to prevent filter damage. Things work differently with two-stroke lawn mower engines, given they do not have an internal oil reservoir, so you may have to empty the oil in a glass to check the oil level. 

What are the Different Lawn Mower Oil Types? 

Car oil is available across a spectrum of different grades, each based on their respective viscosity, and how the oil reacts at different temperatures. 

Viscosity is an important factor to consider when determining which car oil will work well for your mower because both cars and mowers use three common types — SAE 30, SAE 10W-30-, Synthetic SAE 5W-30-, SAE 5W-30-, and Vanguard 15W-50. 

Lawn Mower Oil Types

SAE 30 – this oil has a viscosity rating of 30, and is typically used in smaller air-cooled engines such as the ones in lawnmowers, tractors, and chain saws in warmer temperatures. 

SAE 10W-30 – designed for variable temperature ranges, SAE 10W-30 improves cold weather starting, but may also increase oil consumption. You can use SAE 10W-30 oil instead of SAE 30 oil in your lawn mower, but remember one is more suitable for warmer temperatures, while other geared towards varying temperature ranges.

Synthetic SAE 5W-30 – if you want the best protection in all temperatures, along with improved starting and less oil consumption, Synthetic SAE 5W-30 is a great choice. 

SAE 5W-30 – if you live in extremely cold temperatures, SAE 5W-30 oil comes highly recommended. This oil functions well in temperatures as low as -30ºC and as high as 35ºC, and also in the summer months. 

Vanguard 15W-50 – another type of synthetic oil, Vanguard 15W-50 is a high-performance oil that works well in varying temperature ranges. 

Should I Add Additives to Lawn Mower Oil? 

There’s often great debate on whether to add additives to motor oil or lawn mower oil. Additives can reduce engine damage over time, and increase the service life, and overall performance of your vehicle. 
However, when it comes to lawnmowers that have small engines, it is best to steer clear of additives, as they are designed to work in larger engines. To help you decide whether to add additives to your lawnmower oil, refer to your owner’s manual for manufacturer-recommended advice. 

Can I Use Synthetic Oil in My Lawn Mower?

Synthetic oil is actually good for your lawn mower engine owing to several reasons, most notably because it offers better startup, and a low oil consumption rate. Synthetic oils are acceptable at all temperatures, and even though they may be a little expensive upfront, you don’t have to change them often compared to traditional lawn mower oil. 

What is the Best Car Oil to use in My Lawn Mower? 

Getting back to the main question on whether you can use car oil in your lawn mower, car oil is in fact better for your lawn mower as long as you use the right one. Car oil is also often updated to modern standards, so replenishing the oil in your lawnmower with it will probably prove highly beneficial for the longevity of your machine. The best type of automotive oil to use in your lawnmower is 10W30 for four-stroke engines. 

In the case of two-stroke engines, you will have to figure the right mixing ratio, which usually ranges between 30:1 (4-1/4-oz. of oil to one gallon of gas) to 50:1 (2-1/2-oz. of oil to one gallon of gas. 

Final Thoughts

Standard quality oil for cars and other vehicles is possibly the highest quality lubricant you can get your hands on, making it an optimal choice for four-stroke lawn mower engines.

If you have a two-stroke lawnmower, you can use any two-stroke engine oil such as the Briggs & Stratton 2-Cycle oil shown below. It is also a good idea to check your manufacturer’s user guide on the best oil for your lawn mower model, and when to change the oil, which is usually before every moving season.  

Briggs & Stratton 2-Cycle Easy Mix Motor Oil - 16 Oz. 100036
4,820 Reviews
Briggs & Stratton 2-Cycle Easy Mix Motor Oil - 16 Oz. 100036
  • 2-cycle easy mix motor oil
  • Fuel stabilizer that leaves no residue and prevents plug fouling
  • Recommended for toro, lawn boy, ryan and other 2-cycle outdoor power equipment