The Honda 300 FourTrax typically uses a 10W-40 motorcycle engine oil (API SN or higher). This oil also serves the transmission in the bike’s wet-clutch design, so you’re applying a single oil to lubricate both systems. You can choose conventional, synthetic, or synthetic-blend as long as it meets the motorcycle API specification and Honda’s year-specific guidance.
For context, the 300 FourTrax has a long-standing reputation for reliability, but oil choice matters for protection under heat and heavy use. The exact grade, capacity, and change interval can vary by model year and riding conditions, so it’s important to confirm details in your owner’s manual or with a Honda dealer when in doubt.
Oil types and recommendations
To cover common needs for the TRX300 FourTrax, here are the typical options you can consider:
- 10W-40 motorcycle engine oil, API SN or higher, conventional (mineral) formulation
- 10W-40 motorcycle engine oil, API SN or higher, synthetic or synthetic-blend formulation
- 10W-40 motorcycle engine oil, synthetic-blend option for a cost-efficient upgrade with better protection
All of these options meet Honda’s general requirements for motorcycle engines as long as they are labeled for motorcycle use and meet the appropriate API service category. Avoid automotive engine oils with friction modifiers, and do not mix brands or types without flushing as needed.
Synthetic vs conventional: what matters
Choosing between conventional, synthetic, or a blend primarily affects protection under heat, ease of cold starts, andDrain intervals. Synthetic oils tend to offer better high-temperature stability and longer drain intervals, which can be beneficial for hot climates or heavy use. Conventional oils are perfectly adequate for casual riding and lower-maintenance schedules, typically at a lower cost. In extreme temperatures or demanding riding, synthetic or synthetic-blend 10W-40 is a prudent choice.
Capacity and service intervals
Understanding the oil capacity and how often to change it helps keep the engine and transmission properly lubricated. The TRX300 FourTrax uses engine oil that also lubricates the transmission, so plan your fill accordingly and don’t overfill.
- Check the exact oil capacity and filter-change interval in your model-year manual, since these can vary slightly by year and valve-cover design.
- Typically, the engine oil amount is around one quart (about 1 liter) when changing the filter, but this depends on the model year and the condition of the oil filter.
- Change the oil and the oil filter at the interval recommended by Honda for your riding conditions and climate. Common practice is roughly every 50 hours of riding or once a year, whichever comes first, but always verify against your manual.
- After draining, refill to the proper level with the engine warm, run the engine briefly, then recheck the level on level ground to ensure accuracy.
If you are unsure about the exact capacity or recommended interval for your year, consult the official Honda service manual or your local dealer for precise specifications.
Maintenance tips and cautions
Practical tips can help you maximize oil protection and engine life: use only motorcycle-specific oils, never mix with automotive oils; replace the oil filter with every oil change; clean or replace the drain plug gasket if needed; avoid overfilling and wiping the dipstick clean before rechecking the level; and always run the engine to temperature before checking oil level.
Summary
For most Honda 300 FourTrax models, a 10W-40 motorcycle engine oil (API SN or higher) is the standard recommendation, with options ranging from conventional to synthetic or synthetic blend depending on climate and budget. The oil also lubricates the transmission in these wet-clutch engines, so a single oil fill protects both systems. Always refer to your model-year manual for the exact capacity, grade, and service intervals to ensure optimal protection and performance. Regular oil checks and timely changes help extend the life of your engine and drivetrain.
How many quarts of oil does a 300 fourtrax hold?
NOTE: Honda specifies that the TRX300 engine takes 2.4 quarts of GN4 10W40 oil.
What type of oil goes in a Honda Fourtrax 300?
Synthetic 10W-40 Motor Oil
Valvoline 4-Stroke Motorcycle Full Synthetic 10W-40 Motor Oil 1 Quart. Products highlighted as 'Overall Pick' are: Rated 4+ stars.
What oil does a 1999 Honda Fourtrax 300 take?
10W-40 Oil
Honda OEM Oil Change Kit for 1992-1999 Honda TRX300 FOURTRAX 300 with 10W-40 Oil.
Can I use regular 10W30 in my ATV?
The engines are machined so that the chosen viscosity is most effective. In the example recommendation above, the manufacturer requires grade 10w30, so depending on the start temperature, 0W30, 5W30 or 10W30 would be good choices.