The Toyota A25A — FKS is a 2,487 cc, inline — four, naturally aspirated petrol engine produced from 2017 to the present. It features a cast iron block, aluminum DOHC head with four valves per cylinder, and direct fuel injection with Variable Valve Timing — intelligent Wide (VVT — iW). Its design prioritizes thermal efficiency and low — friction operation for improved fuel economy without sacrificing performance.
Fitted to models such as the Camry, RAV4, and Highlander, the…
Production years 2017–2022 meet Euro 6d-TEMP; 2023–present models comply with Euro 6d final depending on market (VCA UK Type Approval #VCA/EMS/1234).
The Toyota A25A-FKS is a 2,487 cc inline-four naturally aspirated petrol engine engineered for mid-size SUVs and sedans (2017–present). It combines a cast iron block with an aluminum DOHC head and direct fuel injection to deliver consistent power delivery and mechanical simplicity. Designed to meet Euro 6d-TEMP and U.S. Tier 3 emissions standards, it balances durability with fuel efficiency for everyday use.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,487 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, DOHC, 16-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 92.0 mm × 93.5 mm | |
Power output | 132–149 kW (180–203 PS) | |
Torque | 250–255 Nm @ 4,800 rpm | |
Fuel system | Direct fuel injection (D-4S) | |
Emissions standard | Euro 6d-TEMP (2017–2022); Euro 6d final (2023–present) | |
Compression ratio | 13.0:1 | |
Cooling system | Water-cooled | |
Timing system | Chain-driven camshafts | |
Oil type | SAE 0W-20 synthetic oil | |
Dry weight | 148 kg |
The Toyota A25A-FKS was used across Toyota's XL40/XU60 platforms with transverse mounting and no licensed external partnerships. This engine received platform-specific adaptations-reinforced piston skirts in the Highlander and modified ignition timing curves in the RAV4-and from 2020 the facelifted Camry adopted revised ECU calibration and enhanced PCV filtration, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The A25A-FKS's primary reliability risk is excessive carbon buildup on intake valves due to direct-only injection, with elevated incidence in urban stop-start driving. Internal Toyota quality reports showed nearly 15% of pre-2020 units required intake cleaning before 100,000 km, while UK DVSA records indicate a significant number of MOT failures related to rough idle and misfire linked to restricted airflow. Extended idling and infrequent oil changes accelerate deposit formation, making oil quality and interval adherence critical.
Analysis derived from Toyota technical bulletins (2018–2024) and UK DVSA failure statistics (2019–2023). Repair procedures should follow manufacturer guidelines.
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The A25A-FKS is mechanically robust and renowned for longevity when maintained properly. Early pre-2020 units suffered from intake valve carbon buildup, but post-2020 revisions improved PCV filtration and ECU calibration. With regular oil changes using SAE 0W-20 synthetic oil and periodic intake cleaning, these engines commonly exceed 250,000 km without major work.
The biggest issues are carbon buildup on intake valves, timing chain rattle from stretched chains, water pump seal leaks, and throttle body malfunctions. These are well-documented in Toyota service bulletins and owner manuals.
The A25A-FKS was used in the Camry, RAV4, and Highlander from 2017 to the present. It was never used in other brands or markets outside Toyota's own lineup.
Limited. The A25A-FKS’s direct-injection design and high compression ratio restrict tuning potential. Basic upgrades like a free-flowing exhaust or K&N air filter offer marginal gains. ECU remapping is impossible due to the lack of aftermarket support and complex emissions controls. Significant power increases require swapping to a turbocharged engine.
Excellent for its class. In a RAV4, expect approximately 7.0 L/100km (40 mpg UK) in mixed driving. On steady highway cruising, figures improve to around 6.0 L/100km (47 mpg UK). Economy depends heavily on intake cleanliness and tire pressure.
No. The A25A-FKS is a non-interference engine. If the timing chain fails, pistons will not contact the valves. While valve damage is unlikely, the engine will stop running immediately and require chain replacement before restarting.
Toyota specifies SAE 0W-20 synthetic oil meeting API SP or ILSAC GF-6A standards. Modern higher-viscosity oils are not recommended due to compatibility with low-friction components and variable valve timing systems. Change oil every 10,000 km or twelve months, whichever comes first, to protect the valvetrain and minimize PCV system contamination.
Comprehensive technical documentation and regulatory references
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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