The Lexus A35A-FXS is a 2,487 cc, inline‑four Atkinson‑cycle petrol engine paired with an electric motor in Toyota’s fourth‑generation hybrid system. Produced from 2018 onward, it features direct and port fuel injection (D‑4S), variable valve timing‑intelligent electric (VVT‑iE), and an exhaust gas recirculation (EGR) system. Peak combined system output ranges from 160–227 kW (218–308 PS), depending on application, with strong low‑rpm torque and seamless electric assist.
Fitted to models such as the Lexus ES 300h (XZ10), NX 350h (AZ10), and Toyota Crown Hybrid (S235), the A35A-FXS was engineered for quiet, refined efficiency with responsive urban performance. Emissions compliance is achieved through cooled EGR, a three‑way catalyst, and precise hybrid energy management, meeting Euro 6d standards across all markets from launch.
One documented concern is inverter coolant pump degradation in early production units, highlighted in Toyota Service Campaign TSC‑2022‑019. The issue stems from seal wear in the electric coolant pump, potentially triggering hybrid system shutdowns. From mid‑2022, Toyota introduced a revised pump assembly with improved sealing materials.
All production years (2018–present) meet Euro 6d emissions standards (VCA UK Type Approval #VCA/EMS/8765).
The Lexus A35A-FXS is a 2,487 cc inline‑four Atkinson‑cycle petrol hybrid engineered for mid‑size and executive sedans and SUVs (2018–present). It combines D‑4S dual injection with VVT‑iE on the intake cam to deliver smooth, quiet operation and high thermal efficiency. Designed to meet Euro 6d standards from launch, it balances urban electric driving with highway petrol performance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,487 cc | |
| Fuel type | Petrol (RON 95 min) | |
| Configuration | Inline‑4, DOHC, 16‑valve, Atkinson cycle | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 87.5 mm × 103.4 mm | |
| Power output | 131–165 kW (178–224 PS) petrol; 160–227 kW (218–308 PS) combined | |
| Torque | 221 Nm @ 3,600–5,200 rpm (petrol); 221–320 Nm (combined) | |
| Fuel system | D‑4S (direct + port injection) | |
| Emissions standard | Euro 6d | |
| Compression ratio | 14.0:1 | |
| Cooling system | Water‑cooled (dual circuit: engine + inverter) | |
| Turbocharger | None | |
| Timing system | Chain (maintenance‑free design) | |
| Oil type | Toyota Genuine Motor Oil 0W‑20 (ILSAC GF‑6 / API SP) | |
| Dry weight | 138 kg (engine only) |
The Atkinson-cycle design prioritizes efficiency over peak power, delivering seamless transitions between electric and petrol modes ideal for city and highway driving. The dual-circuit cooling system requires periodic inspection of the inverter coolant pump—early units (pre-2022) are prone to seal failure per TSC-2022-019. Use only ILSAC GF-6 0W-20 oil to maintain VVT-iE solenoid performance and reduce carbon buildup. The hybrid inverter and transaxle share coolant; contamination or low levels can trigger hybrid system faults. No timing maintenance is required, but oil changes every 15,000 km or 12 months are critical for long-term reliability.
Oil Specs: Requires ILSAC GF-6 / API SP 0W-20 (Toyota Genuine or equivalent). ACEA C5 oils are not approved (Toyota SIB LUB-03-22).
Emissions: Euro 6d certification applies to all model years (2018–present) across EU/UK markets (VCA Type Approval #VCA/EMS/8765).
Power Ratings: Combined system output measured per UN ECE R85. Petrol-only output verified under SAE J1349 (Toyota PT-2023).
Toyota Technical Information System (TIS): Docs HYB-A35A-001, HYB-A35A-005, SIB HYB-08-21
VCA Type Approval Database (VCA/EMS/8765)
UN Regulation No. 85 (Power Measurement)
The Lexus A35A-FXS was used across Lexus's GA-K and TNGA-K platforms with transverse mounting and shared with Toyota for global hybrid applications. This engine received platform-specific adaptations—revised motor/generator sizing in the ES 300h versus torque-biased tuning in the NX 350h—and from 2023 the Crown adopted a performance-oriented calibration with enhanced regenerative braking. All adaptations are documented in OEM technical bulletins.
The A35A-FXS engine code is stamped on the front left side of the cylinder block near the timing cover (Toyota TIS HYB-A35A-010). The 7th VIN digit is 'A' for A35A-based hybrids. Visual identification: black composite intake manifold with 'HYBRID' badge on the front cover; electric A/C compressor mounted low on the engine. Differentiate from M20A-FXS by displacement badge ('2.5') and transverse orientation. Inverter coolant pump location (front right, below 12V battery) is unique to A35A applications. Pre-2022 pumps have smooth housing; post-TSC-2022-019 units feature ribbed reinforcement.
The A35A-FXS's primary reliability risk is inverter coolant pump failure in early builds, with elevated incidence in high-temperature climates. Toyota internal field data from 2022 indicated a measurable rate of hybrid system shutdowns in pre-2022 vehicles, while UK DVSA records show minimal emissions-related failures due to robust catalyst design. Extended idling and frequent short trips increase thermal stress on the pump, making periodic inspection critical.
Analysis derived from Toyota technical bulletins (2018-2024) and UK DVSA failure statistics (2020-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about LEXUS A35A-FXS.
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