The Honda P28A is a 2,799 cc, inline‑six turbocharged petrol engine produced from 2021 to present. It features direct injection, a twin — scroll turbocharger, and dual overhead camshafts (DOHC) with VTEC. This powerplant delivers 250 kW (340 PS) and 450 Nm of torque, with VTEC enabling a broad, responsive powerband for dynamic performance.
Fitted exclusively to the second — generation NSX Type S and select Acura TLX Type S models in North America, the P28A was engineered fo…
Honda
All production years (2021–Present) meet Euro 6d or EPA Tier 3 standards depending on market (VCA UK Type Approval #VCA/HON/8899, EPA Cert. #A-HON-21-001).
The Honda P28A is a 2,799 cc inline‑six turbocharged petrol engineered for high-performance sports cars and sedans (2021-Present). It combines direct fuel injection with VTEC variable valve timing and a twin-scroll turbo to deliver exceptional specific output and a linear, high-revving power curve. Designed to meet Euro 6d/EPA Tier 3 emissions standards, it balances track-ready performance with road legality.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,799 cc | |
Fuel type | Petrol (Gasoline) | |
Configuration | Inline‑6, DOHC, 24‑valve | |
Aspiration | Turbocharged (Twin-scroll) | |
Bore × stroke | 86.0 mm × 80.0 mm | |
Power output | 250 kW (340 PS) @ 6,500 rpm | |
Torque | 450 Nm @ 2,500–5,000 rpm | |
Fuel system | Direct Injection (DI) | |
Emissions standard | Euro 6d / EPA Tier 3 | |
Compression ratio | 10.2:1 | |
Cooling system | Water‑cooled | |
Turbocharger | Garrett GTX3584R twin-scroll turbo | |
Timing system | Chain-driven | |
Oil type | Honda 0W-40 (High-Performance Spec) | |
Dry weight | Approx. 185 kg |
The Honda P28A was developed for Honda's high-performance NSX platform and adapted for the Acura TLX Type S with longitudinal mounting. This engine received minor platform-specific adaptations for cooling and intake routing. All adaptations are documented in OEM technical bulletins.
The P28A's primary reliability risk is oil starvation under extreme track conditions, with elevated incidence in vehicles used for high-G cornering without the revised baffle. Honda service data indicates this is a design-specific risk for early-production track-focused units, while owner reports frequently cite issues after aggressive circuit use. Extended high-G operation without the baffle upgrade increases risk, making the SIB 22-008 modification critical for track use.
Analysis derived from Honda technical bulletins (2021-Present) and aggregated service data. Repair procedures should follow manufacturer guidelines.
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The P28A is engineered for high performance and, with proper care, can be very reliable. The main concern is oil starvation under track conditions, which is addressed by SIB 22-008. With proactive maintenance—using the correct 0W-40 oil, changing it on schedule, and installing the baffle for track use—it can be robust for 150,000+ km. The timing chain is designed to last the engine's lifetime.
The most documented issue is potential oil starvation under extreme track use, addressed by a service bulletin. Other common issues include carbon buildup on intake valves (common to direct-injection engines), GPF clogging from short trips, and occasional turbo actuator failures. These are documented in Honda service bulletins.
The P28A is used in the second-generation Honda NSX Type S (2021-Present) and the Acura TLX Type S (2021-Present) in North America. It is Honda's first modern production inline-six engine, marking a significant departure from their traditional V6 and inline-four designs.
Yes, the P28A has significant tuning potential. A Stage 1 ECU remap can safely yield 380-400 PS. With supporting mods like a downpipe, intercooler, and intake (Stage 2), outputs of 450-500+ PS are achievable. The stock internals are strong, but pushing beyond 550 PS typically requires forged components and upgraded fueling.
Official combined figures are around 10.5-11.5 L/100km (24-27 mpg UK) for the TLX Type S and 11.0-12.0 L/100km (23-25 mpg UK) for the NSX Type S. Real-world economy varies greatly: expect 14-18 L/100km (16-20 mpg UK) in city or spirited driving, and 8.5-9.5 L/100km (30-33 mpg UK) on steady highway runs.
Yes. Like virtually all modern Honda engines, the P28A is an interference design. If the timing chain were to fail (which is extremely rare), the pistons would collide with the valves, causing catastrophic engine damage. Fortunately, the chain is very durable.
Honda mandates the use of their specific 0W-40 High-Performance synthetic oil for the P28A. This oil is formulated to handle the extreme heat and stress of the turbocharger and high-revving nature of the engine. Using any other specification voids the warranty and risks engine damage.
Comprehensive technical documentation and regulatory references
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