The Lexus A25A-FKS is a 2,487 cc, inline‑four turbocharged petrol engine introduced in 2018. It features Toyota's Dynamic Force architecture with D-4S direct and port fuel injection, VVT-iE (electric) on the intake, and VVT-i (hydraulic) on the exhaust. This combination targets exceptional thermal efficiency (up to 40%) while delivering 152 kW (204 PS) and 250 Nm of torque, providing strong, linear acceleration.
Fitted to models such as the ES 250, NX 250, and RX 250, the A25A-FKS was engineered for refined, quiet operation and responsive performance. Emissions compliance is achieved through a close-coupled three-way catalyst and advanced engine management, meeting stringent Euro 6d and ULEV II standards globally. Its character prioritizes smooth power delivery over outright aggression.
One documented area for attention is the potential for carbon buildup on intake valves, a known characteristic of direct-injection engines without significant port injection contribution under all conditions, as noted in Toyota Technical Service Bulletin EG-0048-21. While not a widespread failure, proactive maintenance is advised. Toyota addressed this in later calibrations by optimizing the D-4S system's port injection usage.
Production years 2018–Present meet Euro 6d-TEMP/Euro 6d standards depending on model year and market (VCA UK Type Approval #VCA/EMS/5678).
The Lexus A25A-FKS is a 2,487 cc inline‑four turbocharged petrol engineered for mid‑size luxury sedans and SUVs (2018-Present). It combines Dynamic Force architecture with D-4S dual injection to deliver smooth, responsive power and class-leading thermal efficiency. Designed to meet Euro 6d and ULEV II standards, it balances performance with low emissions.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,487 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 90.0 mm × 97.6 mm | |
| Power output | 152 kW (204 PS) @ 6,600 rpm | |
| Torque | 250 Nm @ 4,000 - 5,000 rpm | |
| Fuel system | D-4S Direct & Port Injection | |
| Emissions standard | Euro 6d-TEMP / Euro 6d, ULEV II | |
| Compression ratio | 13.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single-scroll turbocharger | |
| Timing system | Chain-driven | |
| Oil type | Toyota Genuine Motor Oil 0W-16 or 0W-20 | |
| Dry weight | Approx. 165 kg |
The high thermal efficiency provides excellent fuel economy but necessitates strict adherence to 0W-16 or 0W-20 oil specifications to maintain variable valve timing (VVT-iE) performance and reduce friction. The D-4S system mitigates, but doesn't eliminate, direct-injection carbon buildup; periodic intake valve cleaning is recommended for high-mileage or stop-start driven vehicles per Toyota SIB EG-0048-21. The electric VVT-iE actuator is robust but sensitive to oil quality. Use of Top Tier fuel is advised to support injector and combustion chamber cleanliness.
Oil Specs: Requires Toyota Genuine Motor Oil 0W-16 (preferred) or 0W-20 (BMW SIB 11 02 17). Critical for VVT-iE and fuel efficiency.
Emissions: Euro 6d-TEMP certification applies to early models; Euro 6d for later builds (VCA Type Approval #VCA/EMS/5678). U.S. models meet ULEV II.
Power Ratings: Measured under SAE J1349 standards. Output consistent across global markets with appropriate fuel (Toyota TIS Doc. A25A-003).
Toyota Technical Information System (TIS): Docs A25A-001, A25A-002, A25A-003, SIB EG-0048-21
VCA Type Approval Database (VCA/EMS/5678)
SAE International: J1349 Engine Power Certification Standards
The Lexus A25A-FKS was developed by Toyota for its global luxury brand, used across Lexus's GA-K platform with transverse mounting. This engine features platform-specific calibrations for noise, vibration, and harshness (NVH) refinement in Lexus applications. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front of the engine block, near the timing cover (Toyota TIS A25A-004). The 8th VIN digit for Lexus models typically indicates engine displacement ('A' for 2.5L). Visually, it can be identified by its compact design, integrated exhaust manifold within the cylinder head, and the 'D-4S' badge on the engine cover. Critical differentiation from the naturally aspirated A25A-FXS: The FKS has a visible turbocharger and associated piping on the front of the engine. Service parts are generally consistent across model years, but ECU calibrations differ; always verify part numbers using the VIN.
The A25A-FKS' primary long-term consideration is intake valve carbon buildup, a common trait in GDI engines with low port injection contribution. Toyota TSB EG-0048-21 acknowledges this for preventative maintenance, while owner data suggests it's manageable with proper fuel and driving habits. Extended low-RPM, low-load driving cycles can accelerate deposit formation, making occasional higher-RPM operation and quality fuel critical.
Analysis derived from Toyota technical bulletins (2018-2024) and aggregated owner-reported data (2020-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about LEXUS A25A-FKS.
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