The 2018 Honda FIT equipped with the 1.5L 4-cylinder engine (Code L15B1 5) is known for its nimble handling, fuel efficiency, and surprising interior versatility. Like any modern internal combustion engine, its longevity and performance rely heavily on the quality of fluids used for maintenance. The original factory oil and filters are designed to meet specific requirements, but switching to high-performance synthetic alternatives can provide superior protection against wear, sludge, and temperature extremes. By using the right lubricants, owners can extend the life of their engine components, improve fuel economy, and ensure the transmission shifts smoothly across all driving conditions.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-16 100% Synthetic Motor Oil – Offers 75% more engine protection against horsepower loss and wear, providing unsurpassed protection for up to 25,000 miles.
- AMSOIL OE 0W-16 100% Synthetic Motor Oil – Fights sludge and deposits with a 100% synthetic formulation, protecting turbochargers 72% better than required by the GM dexos1 Gen 2 specification.
- AMSOIL Oil Filter EA15K13-EA – Provides 99% filtering efficiency at 20 microns and offers greater capacity for small, wear-causing contaminants than competing filters.
- WIX Oil Filter 57356-EA – Premium media offers improvements over original equipment manufacturer-branded filters for enhanced protection.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A unique poly-organic acid formulation that protects the cooling system for up to 150,000 miles or 5 years.
- AMSOIL 100% Synthetic CVT Fluid – Provides exceptional metal-to-metal frictional properties for the automatic transmission, ensuring smooth operation.
- AMSOIL 5W-30 Manual Synchromesh Transmission Fluid – Formulated for maximum protection in synchromesh transmissions, reducing friction, heat, and wear while improving cold weather shifting.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Delivers excellent ABS and traction-control responsiveness with a stable viscosity over a wide temperature range.
Understanding the specific fluid capacities and specifications for your 2018 Honda FIT is the first step in maintaining its performance. The engine oil capacity is approximately 3.5 quarts when the filter is replaced, or 3.3 quarts without the filter change. The manufacturer recommends an oil viscosity of 0W-16 or 0W-20 for all temperatures. When performing an oil change, it is crucial to torque the oil drain plug to 30 ft/lbs and install a new washer on the drain bolt to prevent leaks. The cooling system holds 4 quarts of coolant. For the transmission, the automatic CVT system requires a specific fluid, with a total fill capacity of 6 quarts and an initial fill of 3.6 quarts. If your vehicle is equipped with a manual transmission, the capacity is approximately 3 pints.
The engine oil grade specified by the manufacturer is 0W-16, which is a low-viscosity fluid designed to reduce internal friction and improve fuel economy. However, synthetic options provide better flow characteristics in extreme cold and maintain stability in high heat better than conventional oils. The AMSOIL Signature Series 0W-16 is an ideal choice for those seeking maximum protection and extended drain intervals. It is rated for up to 25,000 miles or one year, whichever comes first. For drivers who prefer a more budget-friendly option that still outperforms conventional oils, the AMSOIL OE 0W-16 is a robust alternative that offers significant protection against sludge and deposits.
Protecting the Transmission and Cooling System
The transmission is a critical component that defines the driving experience of the Honda FIT. For models with a Continuously Variable Transmission (CVT), using the correct fluid is essential. The factory specifications often call for J5KC VTF20, but AMSOIL 100% Synthetic CVT Fluid is formulated to exceed these requirements. It provides exceptional metal-to-metal frictional properties, which helps maintain smooth power delivery and prevents the shudder or slip that can occur in CVTs over time. This fluid is designed to resist oxidation and thermal breakdown, ensuring consistent performance even under severe driving conditions.
Manual transmission owners should look to AMSOIL 5W-30 Manual Synchromesh Transmission Fluid. This fluid is specifically designed for synchromesh transmissions and offers superior protection compared to standard gear oils. It reduces friction, heat, and wear while resisting oxidation and acid buildup. The result is smoother shifting, especially in cold weather, and improved fuel economy. The fluid is compatible with Honda Manual Transmission Fluid specifications, making it a safe and effective upgrade for longevity.
The cooling system in the 2018 Honda FIT is designed to handle a wide range of operating temperatures, but coolant degradation can lead to corrosion and overheating. AMSOIL Passenger Car & Light Truck Antifreeze & Coolant features a unique poly-organic acid (OAT) formulation that is compatible with a wide variety of vehicles and cooling system metals. It protects gaskets and hoses from cracking and drying out. For those who prefer a concentrated coolant, AMSOIL Propylene Glycol Antifreeze offers extended protection up to 150,000 miles or 5 years. Both options are phosphate-, nitrate-, nitrite-, silicate-, borate-, and amine-free, making them safe for all cooling system components.
Fluid Additives and Maintenance
While engine oil and transmission fluid are the primary concerns, brake fluid and fuel additives play a significant role in overall vehicle health. The 2018 Honda FIT requires DOT 3 brake fluid. AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid exceeds DOT 3 and DOT 4 specifications, providing excellent responsiveness for ABS and traction-control systems. It maintains a stable viscosity over a wide temperature range, ensuring consistent pedal feel and safety in wet or dry conditions.
To further enhance engine performance and fuel efficiency, AMSOIL P.i. Performance Improver is highly recommended. This additive helps restore up to 14% horsepower by cleaning carbon deposits from fuel injectors and valves. It is particularly effective in GDI (Gasoline Direct Injection) engines, which are prone to carbon buildup on intake valves. By keeping the fuel system clean, drivers can improve fuel economy and reduce the likelihood of pre-ignition knock. For vehicles that sit idle for extended periods, AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, preventing varnish and gum buildup.
Regular maintenance intervals should be followed to keep the vehicle running smoothly. When changing the oil, always use a high-quality filter to ensure contaminants are removed from the lubricant. The AMSOIL Oil Filter EA15K13-EA is designed to work seamlessly with the Signature Series and OE oils, providing extended service life and superior filtration. If you prefer the WIX brand, the WIX Oil Filter 57356-EA offers premium media that improves upon original equipment manufacturer filters. Both filters help reduce engine wear by capturing small, wear-causing contaminants that standard filters might miss.
About the Vehicle
The 2018 Honda FIT represents the third generation of Honda’s popular subcompact hatchback, a model that has consistently defied the expectations placed upon small cars. Built on the Honda Global Small Car platform, the FIT is renowned for its “magic” rear seats, which feature a 60/40 split that can fold flat for a large cargo area or flip up to transport long items like plants or bicycles. This versatility makes the vehicle an ideal choice for urban dwellers, students, and young families who need a car that is easy to park but capable of handling diverse hauling needs.
Under the hood, the 2018 model year continues to use the 1.5-liter 4-cylinder engine, which delivers a balance of power and efficiency that rivals larger vehicles. The engine produces around 130 horsepower, providing adequate acceleration for city commuting and highway merging without sacrificing fuel economy, which typically hovers around the high 30s to 40 miles per gallon in real-world driving. The interior design emphasizes a futuristic, high-tech feel, often featuring a prominent dashboard layout and a large infotainment screen, which was advanced for its class at the time. Honda’s reputation for reliability is a key factor in the FIT’s enduring popularity, with many owners reporting long lifespans well over 100,000 miles with routine maintenance.
Despite its robust design, the 2018 Honda FIT is not immune to common issues that can affect its longevity. One frequent concern for owners is the buildup of carbon deposits on intake valves, a problem exacerbated by the engine’s design and the use of gasoline direct injection in certain markets. This buildup can lead to rough idling, loss of power, and decreased fuel economy. Using AMSOIL P.i. Performance Improver can help mitigate this issue by cleaning the fuel system and preventing deposit formation. Another potential issue is transmission shudder or hesitation, particularly in CVT models that may suffer from fluid degradation over time. Upgrading to AMSOIL 100% Synthetic CVT Fluid can significantly improve the smoothness of shifts and extend the life of the transmission components.
Brake fluid moisture absorption is another common problem in many Honda vehicles. Over time, brake fluid can absorb water from the atmosphere, which lowers its boiling point and can lead to brake fade or corrosion in the braking system. Replacing the factory fluid with AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid helps maintain a higher boiling point and ensures responsive braking performance even after heavy use. Finally, some owners have reported issues with battery drain or alternator failures in certain model years. While this is often an electrical issue, ensuring the battery terminals and connections are kept clean and free of corrosion can be supported by using AMSOIL Silicone Spray, which protects metal parts and locks out moisture, extending the life of electrical components. By addressing these specific areas with high-quality lubricants and additives, Honda FIT owners can ensure their vehicle remains a reliable and efficient companion for years to come.