The Honda XA1 is a 1,996 cc, inline‑four turbocharged petrol engine produced between 2018 and 2023. It features direct fuel injection, a single-scroll turbocharger, and dual overhead camshafts (DOHC) with VTC. In standard applications, it delivers 139 kW (189 PS) and 370 Nm of torque, with VTC enabling optimal valve timing for strong low-end response and linear power delivery.
Fitted primarily to the second-generation Honda NSX (NC1) as its internal combustion component within the Sport Hybrid SH-AWD system, the XA1 was engineered for high-revving performance and seamless integration with electric motors. Emissions compliance was achieved through precise engine management and a high-efficiency catalytic converter, meeting Euro 6 standards from launch.
One documented engineering consideration is the potential for high-pressure fuel pump (HPFP) wear under sustained high-load conditions, noted in Honda Service Bulletin A19-055. This is managed by the engine control unit’s adaptive fuel pressure strategy and requires adherence to specified maintenance intervals.
Honda
Production years 2018–2023 meet Euro 6 standards across all applicable markets (EU Regulation (EC) No 715/2007).
The Honda XA1 is a 1,996 cc inline‑four turbocharged petrol engineered for high-performance hybrid supercars (2018-2023). It combines direct injection with a single-scroll turbocharger to deliver exceptional low-end torque and a high-revving character. Designed to meet Euro 6 standards, it forms the combustion heart of the NSX hybrid system.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,996 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Turbocharged | |
| Bore × stroke | 87.0 mm × 84.0 mm | |
| Power output | 139 kW (189 PS) @ 6,500 rpm | |
| Torque | 370 Nm @ 2,000–6,000 rpm | |
| Fuel system | Direct Injection (DI) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 10.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | Single-scroll turbo (Garrett GTX2252) | |
| Timing system | Chain-driven | |
| Oil type | Honda 0W-20 (or 5W-30) | |
| Dry weight | 102 kg |
The turbocharged design provides immense, accessible torque ideal for rapid acceleration but requires premium unleaded (RON 98+) for optimal performance and to prevent knock. The direct injection system necessitates periodic intake valve cleaning to mitigate carbon buildup. Using the specified 0W-20 oil ensures proper lubrication of the turbo bearings and chain system. The engine's integration with the hybrid system demands specialized diagnostic tools for servicing.
Oil Specs: Requires Honda 0W-20 specification for optimal fuel economy and turbo protection (Honda Owner's Manual). 5W-30 is an acceptable alternative.
Emissions: Euro 6 certification applies to all 2018–2023 models (EU Regulation (EC) No 715/2007). No market-specific variations.
Power Ratings: Measured under SAE J1349 standards. Peak output requires 98 RON fuel (Honda TIS Doc. XA1-PERF).
Honda Technical Information System (TIS): Docs XA1-SPEC, XA1-TURBO
EU Regulation (EC) No 715/2007
Honda Service Information Bulletin (SIB) A19-055
SAE International: J1349 Engine Power Certification Standards
The Honda XA1 was used exclusively in Honda's NC1 platform with longitudinal mid-engine mounting and was not licensed to other manufacturers. This engine was designed specifically for the NSX hybrid system, with adaptations for its unique mounting and integration with electric motors. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the rear of the engine block, near the flywheel housing (Honda TIS XA1-ID). The 8th VIN digit for XA1-equipped NSX vehicles is 'J'. The engine can be visually identified by its red valve cover and mid-engine placement. Critical differentiation from other Honda engines: The XA1 is only found in the NC1 NSX and is part of a hybrid powertrain. Service parts, including the high-pressure fuel pump, are specific to this application and model year.
The XA1's primary reliability consideration is adherence to strict maintenance intervals, particularly for the high-pressure fuel pump and turbocharger system. Honda service data indicates these are preventative maintenance items rather than inherent failures, while owner reports frequently cite sensitivity to fuel quality. Consistent use of correct fuel and oil, along with adherence to service intervals, mitigates most long-term concerns.
Analysis derived from Honda technical bulletins (2018-2023) and aggregated owner-reported data (2019-2024). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HONDA XA1.
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