Can I Use Synthetic Oil In My John Deere Riding Lawn Mower?

John Deere riding mowers come with s specific oil formulated for that engine, and the manual will tell you the type of oil it’s supposed to use. However, is that all there is to it? Cars and trucks come the same way, with manuals full of oil-specific literature. But everyone knows you can use different oils in a car. Why not in a John Deere?

While most John Deere riding lawn mowers recommend 10W-30 and 5W-30, there’s nothing that says it can’t be a synthetic version of either. John Deere develops a specific blend of synthetic oil for use in John Deere riding mowers, so there is no reason you shouldn’t use it. 

There is a prevailing myth that makes its rounds when it comes to engines, whether its car engines or small engines. The myth is that synthetic oil should only be used when the engine has reached a certain point in its lifespan. 

This prevailing “wisdom” is not really wisdom at all, and synthetic oils are perfectly fine for engines of all ages. 

Synthetic Oil Versus Mineral Oil for a John Deere Riding Lawn Mower

While there is nothing wrong with standard oil (mineral) oil in your John Deere, there are almost zero advantages to using it over a synthetic or even a synthetic blend. Synthetic oil is superior in almost every way. 

  • Synthetic oil operates better at extreme temperatures (hot/cold)
  • Synthetic oil protects the engine from wear and tear better than mineral oil
  • Resists breaking down as quickly as mineral oil
  • Synthetic oil resists breakdown at higher temperatures, and four-stroke engines get seriously hot
  • Synthetic oil fights sludge and deposits more efficiently than mineral oil

As in car engines, synthetic oil lasts much longer in a John Deere riding mower than mineral oil. While synthetic and synthetic blend oils are slightly more expensive, you will find yourself changing the oil with far less frequency, saving you money over time. 

The only difference between a lawn mower and a car is that you change your oil based on miles in a car, and you change it based on hours of use in a riding lawn mower. 

How Often Should You Change the Oil in a John Deere Riding Mower?

The general consensus is that you should change your oil after every 50 hours of use. But, of course, if you have a massive lawn and spend a lot of time on your John Deere, you may reach 50 hours well before the season for mowing has come and gone. 

The good thing about synthetic oil is that you don’t have to change it nearly as often as mineral oil. So even if you exceed 50 hours in a single mowing season, you can get away with waiting until the start of the next season before you change your oil again. 

You should also stick with a John Deere synthetic oil or a John Deere synthetic oil blend. It certainly won’t hurt your John Deere riding mower if you use synthetic oil that doesn’t carry the John Deere label. 

However, John Deere manufactures their synthetic and synthetic blend oils specifically for their lawn mowers. 

John Deere does sell a synthetic oil, but it only comes in 0W-40 weight. However, you can opt for synthetic oil from another brand. John Deere goes with the lowest bidder to make name-brand John Deere oils, kind of like a private label brand. 

While there is no information covering all of the brands behind John Deere oils, we know that John Deere has used MobilShellExxonChevronNorthland Oil, and Petro Canada to manufacture their John Deere oils. 

So, you can choose any of those brands of 10W-30 synthetic oils to place in your John Deere riding mower. They won’t harm your engine and will benefit it in a variety of ways that we listed above. 

John Deere only recommends John Deere oils because, of course, they do. Buying John Deere oils for your John Deere mower makes John Deere money. 

Picking the Right Synthetic Oil for a John Deere Riding Mower

You don’t want to change the weight of the oil just because you are switching from standard mineral oil to synthetic oil. If the John Deere riding mower calls for 10W-30 oil, use 10W-30 synthetic oil or a 10W-30 synthetic blend. 

The first number in 10W-30 stands for the thickness of the oil, with higher numbers indicating a thicker oil. Synthetic oils are generally a little lighter and smoother than mineral oils, so you get a slicker oil with 10W-30 synthetic over 10W-30 mineral oil.

Synthetic and synthetic blend oils will retain their viscosity and ability to flow and lubricate at higher temperatures than mineral oil can stand. So it’s a better deal all around. The “W” stands for “Winter.” It indicates how well the oil flows based on the preceding number. 

The number 10 is thick enough to flow well as synthetic oil, withstanding the natural breakdown process that occurs at higher temperatures, and still retains those capabilities when it’s cold. 

That makes synthetic the better choice because its range and capabilities are not easily lost in varying temperatures. If John Deere recommends 10W-30, you can’t go wrong with a 10W-30 synthetic blend, no matter where you live or the severity of the seasons. 

You should always check your John Deere manual to ensure that it recommends 10W-30 or something else. Of course, it will only recommend John Deere, but that’s irrelevant. It’s the number you’re looking for, and you can choose a synthetic version of that number rather than John Deere mineral oil. 

John Deere Temperature Recommendations

This is something worth paying attention to as well. You also must remember that synthetic oil gives you some more leeway in colder or hotter temperatures simply because of its versatility. 

If you live in southern climates, you will often see recommendations of 15W-40 from John Deere and other lawn mower experts. According to John Deere, 15W-40 is the pinnacle of protection, viscosity, and durability but only when the temperatures in your region don’t drop below zero. 

It’s hard to imagine why you would crank your riding lawnmower up in -0°F temperatures, but the warning is there nonetheless. For those who live in Tennessee or farther north, 0° temperatures happen, with more and more frequency the farther north you go. 

If you live in an area where the temperature drops that low, John Deere recommends 10W-30. According to John Deere, 10W-30 protects as low as -4°F. Of course, with synthetic oil, you can expect a little better. Some people use their riding lawnmowers as snow plows, so the 10W-30 would benefit them.

If you live in a frigid climate, John Deere recommends 5W-30, which can handle temperatures that drop down to -22°F without having any issues. The thinner viscosity of the 5W-30 oil keeps it flowing, even in freezing temperatures. 

These are all recommendations that come directly from John Deere. A synthetic blend or a full synthetic alternative will provide even more protection during freezing weather. 


You should always use the oil type, and weight recommended for your specific mower. You can usually switch to a synthetic version of the same oil without any issues. 

Synthetic oil will often provide better protection and performance than mineral oil, especially in extreme temperatures. 

If you have questions about what oil to use in your John Deere riding mower, consult your owner’s manual or contact a John Deere dealer. They will be able to help you choose the right oil for your mower and climate.

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