The Toyota 1KR-FE is a 998 cc, inline‑three, naturally aspirated petrol engine produced from 2004 to 2023. It features an aluminium alloy block and head, dual overhead camshafts (DOHC), and 12 valves. Its compact, lightweight design prioritises fuel efficiency and urban drivability, making it ideal for Toyota's global A-segment vehicles.
Fitted to models such as the Aygo (AB10), Yaris (XP90), and C-HR (AX10 in select markets), the 1KR-FE was engineered for low running costs and nimble city performance. Emissions compliance evolved over its lifespan, meeting Euro 4 standards initially and later Euro 6 with revised engine management and exhaust systems.
One documented concern is premature wear of the timing chain tensioner in high-mileage units, potentially leading to chain noise and slack. This issue, noted in Toyota Technical Service Bulletins for specific production batches, was often linked to extended oil change intervals. Toyota later revised the tensioner design and recommended more frequent inspections for preventative maintenance.
Production years 2004–2010 meet Euro 4 standards; 2011–2023 models meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/9123).
The Toyota 1KR-FE is a 998 cc inline‑three petrol engine engineered for city cars and compact crossovers (2004-2023). It combines a DOHC valvetrain with VVT‑i variable timing to deliver responsive low-end torque and exceptional fuel economy. Designed to meet Euro 4 and Euro 6 emissions standards, it balances minimal environmental impact with low-cost ownership.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 998 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑3, DOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 71.0 mm × 84.0 mm | |
| Power output | 50–54 kW (68–73 PS) | |
| Torque | 93–95 Nm @ 3,600 rpm | |
| Fuel system | Sequential multi-port fuel injection | |
| Emissions standard | Euro 4 (2004-2010); Euro 6 (2011-2023) | |
| Compression ratio | 11.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | SAE 5W-30 (API SN) | |
| Dry weight | 73 kg |
The three-cylinder design offers excellent fuel economy but requires strict adherence to 10,000 km oil change intervals to prevent timing chain tensioner wear. Using the correct low-viscosity oil (5W-30 API SN) is critical for optimal lubrication and fuel efficiency. The VVT-i system is generally robust but can develop faults if oil sludge accumulates; regular oil changes prevent this. The lightweight engine responds well to light-footed driving, making it ideal for urban environments.
Oil Specs: Requires SAE 5W-30 meeting API SN specification (Toyota Owner's Manual 2015). Modern API SP is acceptable.
Emissions: Euro 4 certification applies to 2004-2010 models; Euro 6 for 2011-2023 (VCA Type Approval #VCA/EMS/9123).
Power Ratings: Measured under SAE J245/J1995 standards. Output is consistent across model years (Toyota Group PT-2018).
Toyota Repair Manual RM127E
Toyota Electronic Parts Catalog (EPC) #TJ-1KR
VCA Type Approval Database (VCA/EMS/9123)
SAE International: J245 Engine Power Test Code
The Toyota 1KR-FE was used across Toyota's AB/XP/AX platforms with transverse mounting. This engine received platform-specific adaptations-revised engine mounts for the C-HR and different intake manifolds for the Aygo-creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the flat machined surface at the front of the cylinder block, near the alternator (Toyota Repair Manual RM127E). The 1KR-FE is visually identified by its compact three-cylinder layout, single plastic engine cover, and the "VVT-i" badge. Critical differentiation from the 1.3L 1NR-FE: The 1KR has a 998 cc displacement (71.0 mm bore x 84.0 mm stroke) versus the 1NR's 1,329 cc. The engine block and cylinder head castings are significantly smaller.
The 1KR-FE's primary reliability risk is timing chain tensioner wear, with elevated incidence in high-mileage or poorly maintained engines. Toyota service data indicated a notable number of units required tensioner inspection after 150,000 km, while owner reports frequently cite minor oil leaks as a common maintenance item. Infrequent oil changes and use of incorrect viscosity oil accelerate wear, making adherence to the maintenance schedule critical.
Analysis derived from Toyota technical bulletins (2004-2023) and owner-reported failure statistics (compiled 2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about TOYOTA 1KR-FE.
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