HKS 52001-AK125 Super Turbo Racing 5W-40 Full Synthetic Engine Oil 4L LSPI SN+

Vehicle Fitment

• Universal - suitable for all gasoline turbocharged engines specifying a 5W-40 (#W40) viscosity grade, including modified and high-boost applications
• Specifically developed and well-suited for small displacement direct injection turbocharged engines, including: Suzuki K14C, Toyota 8NR-FTS, Honda L15B and L15C, Nissan SR20DET, Mitsubishi 4G63 and 4B11, and similar downsized turbo platforms

Fitment Notes

• Universal fitment - verify your vehicle manufacturer's recommended oil viscosity grade before use; this oil is intended for engines specifying 5W-40 or equivalent #W40 grade
• Compatible with both stock-tuned and modified turbocharged gasoline engines - particularly well suited for high compression, high boost direct injection turbo engines that may generate LSPI (Low Speed Pre-Ignition) events even when using a high-viscosity oil
• Not suitable for diesel engines or naturally aspirated engines requiring a different viscosity grade
• For the same 5W-40 Super Turbo Racing formula in a 1L can, see HKS 52001-AK124

Features

• 100% synthetic base oil - provides superior film strength, thermal stability, and oxidation resistance compared to mineral or semi-synthetic base oils, maintaining viscosity and lubrication quality under sustained high-temperature turbo engine operation
• LSPI (Low Speed Pre-Ignition) protection - specially formulated with additives to prevent LSPI, a destructive pre-ignition event that occurs in modern downsized turbocharged direct injection engines, particularly at low RPM under high load conditions. LSPI is typically associated with low-viscosity oils, but can also occur in high-compression, high-boost tuned DI turbo engines even with higher-viscosity oils. The HKS Super Racing formula addresses this more demanding scenario directly
• SN+ API rating - complies with the SN+ standard, which specifically addresses LSPI protection requirements introduced for modern turbocharged gasoline direct injection engines
• 5W-40 viscosity - provides broad cold-start protection down to -35°C (W5 cold-cranking performance) combined with the robust high-temperature film strength of a 40-weight oil, making it suitable across a wide range of ambient temperatures and operating conditions
• Allowable maximum operating temperature of 140°C - engineered to maintain viscosity and lubrication integrity under the extreme thermal conditions generated by turbocharged engines running at elevated boost, including track and motorsport use
• Redesigned formulation based on HKS's bestselling "Super Oil" series - HKS's most popular oil line updated with modern additive technology specifically targeting the LSPI protection demands of current-generation downsized turbo engines while preserving the protective characteristics that made the original Super Oil series a benchmark in the JDM performance oil segment
• Viscosity and additive formulation optimized per engine specification - HKS selects the best base oil grade and additive blend for each viscosity variant in the Super Turbo Racing line rather than using a generic carrier formula
• 4-liter container - typical service fill volume for most 4-cylinder turbocharged engines (capacity depending on sump size and whether oil filter is changed simultaneously)

Specifications

• Part Number: 52001-AK125
• Product Name: Super Turbo Racing Oil
• Viscosity Grade: 5W-40
• Volume: 4 liters
• Base Oil: 100% Synthetic
• API Standard: SN+ compliant
• LSPI Protection: Yes
• Maximum Allowable Temperature (High): 140°C
• Equivalent Stock Grade: #W40
• Suitable Engine Types: Turbocharged gasoline (DI and port injection)
• GTIN: 4957266455852

Included Components

• 1x 4-liter can of HKS Super Turbo Racing 5W-40 engine oil

Product Description

The HKS 52001-AK125 Super Turbo Racing 5W-40 is a 4-liter can of 100% synthetic engine oil developed as the evolved successor to HKS's long-running bestselling Super Oil series. The defining advancement in the Super Turbo Racing line is its dedicated LSPI (Low Speed Pre-Ignition) protection - a critical formulation requirement for modern downsized turbocharged direct injection engines. LSPI is a destructive pre-ignition event that tends to occur in DI turbo engines at low RPM under sudden high-load conditions, such as acceleration from low speed in a high gear. The phenomenon is generally understood to be linked to the interaction between fuel droplets, engine oil mist, and combustion chamber conditions; conventional wisdom associates it primarily with low-viscosity oils, but in high-compression, high-boost tuned DI turbo engines, the combustion environment can produce LSPI even with heavier-weight oils. The HKS Super Racing formulation is designed as a high-viscosity, LSPI-capable oil precisely for this more demanding use case - modified and performance-tuned engines where stock-grade protective assumptions no longer apply.

The 5W-40 viscosity grade provides wide operational range: the W5 cold-start rating ensures reliable cranking and oil film establishment in low ambient temperatures, while the 40-weight hot viscosity delivers robust film thickness under the sustained high temperatures and loads of boosted engines. The 100% synthetic base oil maintains its viscosity stability and oxidation resistance throughout extended service intervals and high operating temperatures up to 140°C - conditions that accelerate the breakdown of mineral and semi-synthetic formulations and can lead to viscosity shear and deposit formation in turbocharger bearings and piston ring grooves. The SN+ API standard confirms the formulation meets the specific LSPI-protection benchmarks established for modern GDI turbocharged gasoline engine applications.

This oil is universal in application and suitable for any turbocharged gasoline engine specifying a 5W-40 or equivalent #W40 viscosity grade. HKS highlights compatibility with a broad range of popular performance and downsized turbo platforms including the Suzuki K14C, Toyota 8NR-FTS, Honda L15B and L15C, Nissan SR20DET, Mitsubishi 4G63 and 4B11 - covering everything from modern downsized street turbo engines to classic JDM performance platforms. For applications requiring a smaller service fill or top-off quantity, the same 5W-40 Super Turbo Racing formula is available in a 1-liter can (HKS 52001-AK124).