Modern gasoline vehicles face complex emissions challenges. Port fuel injection (PFI) engines primarily produce gaseous pollutants (CO, HC, NOx), while gasoline direct injection (GDI) engines add particulate matter (PM) and particulate number (PN) concerns. Hybrid electric vehicles (HEV, PHEV) operate at low exhaust temperatures with infrequent engine operation, making catalyst light-off difficult. We provide complete, validated gasoline aftertreatment solutions for passenger cars, SUVs, light trucks, and hybrid platforms, meeting Euro 7, EPA Tier 3, China 7, and global equivalents.
Gasoline engines operate near stoichiometric (air-fuel ratio 14.7:1), enabling the highly efficient Three-Way Catalyst (TWC) to simultaneously convert CO, HC, and NOx. GDI engines produce fine soot particles that require filtration. Hybrids run intermittently and cool, demanding rapid light-off strategies. Our systems integrate multiple technologies into compact, thermally managed packages.
Port Fuel Injection (PFI) – Base configuration:
Engine → Close-coupled TWC → Tailpipe
Gasoline Direct Injection (GDI) – Standard configuration:
Engine → Close-coupled TWC → Underfloor GPF → Tailpipe
GDI with advanced particulate control (Euro 7 / China 7):
Engine → Close-coupled cGPF (Four-Way Catalyst) → Tailpipe
Hybrid Electric Vehicle (HEV/PHEV) – Low-temperature configuration:
Engine → Electrically Heated Catalyst (eHC) → Close-coupled TWC → Underfloor GPF → Tailpipe
Converts CO, HC, and NOx simultaneously under stoichiometric conditions. Cordierite honeycomb (400–900 cpsi, 2–4 mil wall) with Pd/Rh washcoat (1–4 g/L Pd, 0.1–0.3 g/L Rh). Ceria-zirconia provides oxygen storage capacity to buffer air-fuel fluctuations. Conversion efficiency: >98% CO, >95% HC, >95% NOx. Light-off temperature (T50): 200–250°C.
Captures soot from GDI engines. Wall-flow cordierite or SiC substrate (200–300 cpsi, 8–10 mil wall, 50–60% porosity). Filtration efficiency: >99% for particles >23 nm. Passive regeneration occurs during normal driving (exhaust 500–700°C). Service life: 150,000+ km.
Combines TWC and GPF in one brick. Saves space, reduces backpressure, lowers cost. Provides simultaneous gas conversion (>95%) and particulate filtration (>99%).
Used in hybrid and Euro 7 applications. Resistive heating embedded in metallic or ceramic substrate. Reaches 300°C in under 10 seconds from cold start, eliminating cold-start emissions spikes. Powered by 48V supply, critical for plug-in hybrids.
Pollutant | PFI Engine Out | GDI Engine Out | After Aftertreatment | Efficiency |
CO | 1–3% | 0.5–2% | <0.1% (<100 ppm) | >98% |
HC | 300–800 ppm | 100–400 ppm | <50 ppm | >95% |
NOx | 200–800 ppm | 100–500 ppm | <50 ppm | >95% |
PN | 1×10¹⁰ #/km | 1×10¹²–1×10¹³ #/km | <6×10¹¹ #/km | >99% |
Vehicle Type | Engine | Aftertreatment Configuration | Key Requirements |
Compact car (PFI) | 1.0–1.6L | Close-coupled TWC | Low cost, 150k km durability |
Midsize sedan (GDI) | 1.5–2.5L | TWC + underfloor GPF | Balance gas and particulate control |
SUV / Crossover (GDI) | 2.0–3.5L | TWC + GPF or cGPF | High flow, low backpressure |
Performance / Turbo GDI | 2.0–4.0L | Dual TWC + GPF | Thermal durability >1,000°C |
Full hybrid (HEV) | 1.5–2.5L | eHC + TWC + GPF | Fast light-off, infrequent cycles |
Plug-in hybrid (PHEV) | 1.5–2.0L | eHC + cGPF | Ultra-low cold-start emissions |
Engineered for Euro 7 (RDE including cold start, short trips, high load), EPA Tier 3, China 7. Compliant across all real driving conditions.
Close-coupled positioning captures heat immediately. Thin-wall substrates (2 mil, 900 cpsi) reduce thermal mass. eHC option achieves 300°C in under 10 seconds. Light-off in 15–30 seconds versus 60–90 seconds for conventional designs.
Cordierite substrates withstand 1,050°C continuous, 1,200°C peak. La-stabilized alumina washcoat resists sintering. Multi-layer TWC protects Rh from poisoning.
GPF adds only 2–5 kPa at rated power. cGPF reduces backpressure further. High-porosity substrates (60%+) minimize flow restriction.
Passive thermal management (insulation, heat retention). Electrically heated option for PHEVs. GPF regeneration is passive.
Dual oxygen sensors monitor TWC efficiency. Differential pressure sensor for GPF soot load. Temperature sensors. Catalyst aging model for remaining useful life.
Service Area | Description |
Technology selection | TWC only, TWC+GPF, or cGPF based on engine type and emissions target |
Substrate engineering | Cell density (400–900 cpsi), wall thickness (2–5 mil), volume (engine displacement × 1.0–1.5) |
Washcoat formulation | OSC level, PGM loading optimized for cost and performance |
Canning & packaging | Close-coupled or underfloor, heat shields, mounting brackets |
eHC integration | 48V power supply, heater control module, thermal management |
Calibration | ECU integration, AFR control, catalyst monitoring, OBD development |
Millions of TWC and GPF units in production. Validated to Euro 6d, EPA Tier 3, China 6b.
In-house substrate extrusion, washcoat formulation, catalyst coating, canning, and dosing controls. This provides single-source accountability.
Specialized eHC and low-temperature TWC for HEV/PHEV. Cold-start emissions reduced by 70–90% compared to conventional catalysts.
Pd-Rh formulations optimized for current metal prices. cGPF reduces total PGM by eliminating separate TWC brick.
From small-displacement PFI city cars to high-performance GDI SUVs and next-generation plug-in hybrids, our gasoline aftertreatment solutions deliver compliance, durability, and value. Partner with us to engineer your path to clean gasoline operation.