Small engines like those found in lawn mowers, chainsaws, generators, and other outdoor power equipment can benefit from using synthetic oil. Synthetic oil has some advantages over conventional oil that can extend the life of small engines. However, there are also some important considerations when using synthetic oil in small engines. This article will examine if you can use synthetic oil in small engines, the pros and cons, and best practices.
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Quick Answers
– Yes, you can use synthetic oil in small engines. Many small engine manufacturers approve the use of synthetic oils.
– Synthetic oil flows better at low temperatures, resists oxidation and sludging, and provides better protection. This can extend the oil change interval and engine life.
– However, synthetic oil can be more expensive than conventional oil. It may also leak more due to smaller molecule size.
– Use synthetic oil of the proper viscosity range recommended by your engine manufacturer. Fully synthetic 5W-30 or 10W-30 oils are commonly recommended.
– Changing to synthetic oil won’t harm your engine as long as you use the right viscosity and quality oil. Slowly transitioning to synthetic by mixing oils is unnecessary.
– Synthetic oil should be changed at the interval recommended by the engine manufacturer, typically every 50 hours of use or annually. It does not necessarily need changed less often than conventional oil.
Can You Use Synthetic Oil in Small Engines?
Yes, you can safely use synthetic oil in most small engines, including lawn mower engines. Many major small engine manufacturers approve or even recommend using synthetic oil. This includes brands like Briggs & Stratton, Honda, Kawasaki, Kohler, and Tecumseh.
Consult your owner’s manual to verify if the engine manufacturer approves synthetic oil use. If synthetic oil is approved, you can switch to using it without issue as long as you choose the proper viscosity grade.
Manufacturer Recommendations
Here are the synthetic oil recommendations from several major small engine manufacturers:
| Manufacturer | Synthetic Oil Recommendation |
| Briggs & Stratton | Approved – 10W-30 or 5W-30 synthetic oils meeting ILSAC GF-5 specification |
| Honda | Recommended – 10W-30 synthetic oil |
| Kawasaki | Approved – 10W-40 or 10W-30 synthetic oils |
| Kohler | Approved – 10W-30 synthetic oil |
| Tecumseh | Approved – 5W-30 synthetic oils |
As you can see, most major small engine brands approve using synthetic oil as long as you choose the proper viscosity grade, usually 5W-30 or 10W-30 weight.
Pros and Cons of Synthetic Oil in Small Engines
Synthetic oil has some advantages that can benefit small engines but also some disadvantages to consider.
Pros
Here are the main benefits of using synthetic oil:
– Better cold weather performance – Synthetic oil flows more easily at low temperatures, allowing the engine to start and circulate oil faster. This can reduce wear during cold starts.
– Enhanced high temperature protection – Synthetic oil better withstands high engine temperatures without oxidizing or thickening. This reduces sludge buildup.
– Lower volatility – Less oil evaporation occurs with synthetics, reducing oil loss over time.
– Increased shear stability – Synthetics resist viscosity breakdown better under high engine loads and RPMs.
– Longer oil change intervals – The advanced properties allow synthetic oil change intervals to be extended, sometimes up to 2X the standard interval.
– Potential fuel efficiency gains – Reduced friction from synthetic oil can provide up to 3-4% better fuel economy.
Overall, synthetic’s excellent resistance to oxidation, sludging, and other issues can significantly extend the life of a small engine.
Cons
Here are the downsides associated with synthetic oil:
– Higher cost – Synthetic oil can cost 2-5X more than conventional oil per quart. This increases the operating costs.
– Potential seal incompatibility – Some older small engines may have seals not designed for synthetic’s smaller molecules, causing minor leaks.
– No verifiable change interval – While synthetic may enable longer change intervals, most manufacturers still specify the same change frequency.
– Over-reliance on synthetics – There is a slight risk of relying only on the oil and neglecting other maintenance.
Overall, the disadvantages of synthetic oil are relatively minor. Cost tends to be the primary downside that prevents widespread synthetic adoption. Leaks are uncommon and can be resolved with seal replacements if needed.
Best Practices for Using Synthetic in Small Engines
Follow these best practices when switching to synthetic oil:
– Consult your manual to ensure synthetic oil is approved and identify the proper viscosity grade. Using the manufacturer’s recommended oil weight is critical.
– There is no need to gradually transition to synthetic by mixing conventional and synthetic oils. You can safely switch completely to synthetic immediately.
– Do not exceed the advised oil change interval. Most manufacturers still recommend changing synthetic oil at the standard intervals.
– Check for leaks periodically when first transitioning to synthetics. Address any persistent leaks by replacing worn seals and gaskets.
– Continue to follow the engine’s maintenance schedule, don’t neglect air filters, spark plugs, blade sharpening, etc. just because you use synthetic oil.
Following the engine manufacturer’s specifications and advice when switching to synthetic oil will ensure you safely realize the benefits while avoiding potential issues.
Frequently Asked Questions
Is synthetic oil better for small engines?
Synthetic oil is generally better for small engines due to superior thermal stability and resistance to oxidation at high temperatures. Synthetic oil keeps your engine cleaner while providing excellent wear protection.
Why would synthetic oil cause leaks in a small engine?
Synthetic oils have smaller molecule sizes that can squeeze through older seals and gaskets not designed for it. Upgrading well-worn seals prevents this minor issue.
Do you mix synthetic and regular oil for small engines?
No, there is no need to mix conventional and synthetic oils when transitioning. It provides no benefit and you can switch completely to synthetic right away.
How often should you change synthetic oil in small engines?
Follow the manufacturer’s recommendations, typically changing synthetic oil every 50 hours of runtime or annually. Do not extend changes beyond intervals unless specified.
What weight synthetic oil should I use in my lawn mower?
Use the viscosity grade recommended by your mower’s engine manufacturer, usually SAE 5W-30 or 10W-30 synthetic oil. Consult your owner’s manual for the proper synthetic oil weight.
The Bottom Line
Synthetic oil can provide excellent benefits for small engines, including better cold weather starting, reduced sludge, and extended engine life. Most small engine manufacturers approve using synthetic oils, as long as you choose the proper viscosity recommended for the engine. While synthetics cost a bit more, the improvements in engine protection and performance are worth it for many consumers. Follow your engine manufacturer’s maintenance instructions for synthetic oil changes to maximize the benefits while avoiding potential drawbacks like leaks. With proper care, synthetic oil can be a worthwhile investment for your small engine.