Euro 7 for passenger cars and light vans is evolutionary rather than radical: most lab tailpipe limits stay near Euro 6, but durability, particle counting, on-road conformity, and monitoring tighten. The headline shifts are 200,000 km/10‑year emissions durability, counting ultrafine particles down to 10 nm (PN10) and extending PN limits to all spark‑ignition engines, plus on‑board monitoring of real‑world emissions performance. These changes push larger, more robust aftertreatment, better cold‑start thermal management, and sensor-heavy diagnostics. The net effect is cleaner lifetime performance with modest fuel and cost penalties, particularly for small diesel and port‑fuel‑injected gasoline cars.
Euro 7 reframes compliance from “pass the lab test new” to “stay clean for a decade.” For light-duty gasoline and diesel, it largely carries forward Euro 6 tailpipe mass limits but expands the operating envelope (more cold starts/short trips, broader ambient conditions) and demands longer in‑use durability. It also closes particle loopholes by moving from PN23 to PN10 and bringing port‑fuel‑injected (PFI) gasoline into the particle cap. The core idea is to ensure catalysts, filters, and control strategies remain effective across real roads and through 200,000 km. That means higher precious‑metal loadings, more volume/front‑loading of catalysts and filters for faster light‑off, tighter lambda/NOx control, and continuous checks via on‑board monitoring (OBM) rather than relying solely on periodic inspections.
Durability requirements: the emissions control system must meet limits for 200,000 km or 10 years (up from ~160,000 km/8 years under Euro 6). Manufacturers must demonstrate durability with accelerated aging and in‑use testing. Practically, that drives: larger/closer‑coupled three‑way catalysts (TWCs) for gasoline and higher-volume, low‑temperature‑active SCR+DPF systems for diesels; higher precious‑metal loadings to resist thermal sintering and poisoning; tighter oil/ash control (low‑SAPS lubricants) to protect GPF/DPF; and thermal strategies (insulation, catalyst underfloor+close‑coupled staging, or electric heaters) to reach ~250–300°C TWC light‑off and ~180–200°C SCR activity quickly in cold starts. PN/NOx thresholds and test scope: lab NOx limits remain at 60 mg/km for gasoline and 80 mg/km for diesel.
Particle Number is tightened by counting down to 10 nm (PN10) and extending the PN limit (6.0×10^11 #/km) to all spark‑ignition engines, not just GDI; this effectively mandates gasoline particulate filters (GPFs) on PFI applications with high cold‑start or acceleration PN. Diesels already meeting 6.0×10^11 #/km with DPFs must now control ultrafines too (PN10), reinforcing high‑efficiency filtration and low‑soot calibration. Ammonia slip is capped (≈10 ppm), and off‑cycle greenhouse species (e.g., N2O from diesel SCR) are constrained, pushing careful dosing and catalyst selection. On‑road RDE conformity tightens so effective NOx/PN must be achieved in a wider temperature range (including sub‑freezing) and short urban trips; conformity margins are small enough that designs need lab‑like performance on the road.
On‑board monitoring (OBM) and diagnostics: beyond traditional OBD, Euro 7 requires continuous estimation/measurement of key emissions (NOx sensors on diesel, PM sensors downstream of filters, oxygen/AFR fidelity, catalyst/GPF efficiency models) and logging of exceedances. The system must alert drivers when emissions degrade materially and store data for authorities/service tools, including lifetime emissions performance and tampering detection (e.g., DEF quality/level, sensor plausibility). For gasoline, model‑based OBM tracks catalyst conversion and misfire/over‑rich events; for diesel, dual NOx sensors verify SCR efficiency and enable adaptive dosing. The monitoring thresholds are set close to legal limits to catch real deterioration rather than only gross failures, so sensor robustness and drift control are critical.
Trade‑offs, mechanisms, and typical countermeasures: to hit PN10 and urban cold‑start targets, gasoline applications adopt close‑coupled GPFs with low‑pressure‑drop substrates; calibrations favor slightly richer warm‑up or spark retard with exhaust enthalpy management, sometimes assisted by electric heating (12/48 V) to cut the first 30–60 seconds’ emissions. Diesels rely on faster light‑off via close‑coupled DOC+DPF+SCR (“SDPF” bricks) and higher urea dosing, potentially dual‑dosing layouts, with active thermal management to keep SCR above ~180°C in urban duty. These measures can add 0.5–2% fuel penalty (backpressure, warm‑up enrichment, or heating), but they greatly reduce cold‑start NOx/PN. Over 200,000 km, ash accumulation and PGM sintering are managed by larger volumes, optimized washcoat, and tighter oil specs.
Cost pressures: adding a GPF to PFI gasoline typically adds €100–€200 bill‑of‑materials; GDI variants may see €50–€150 for PN10‑capable filters and calibration updates. Diesel systems need more SCR volume/dual dosing and higher‑spec sensors, adding roughly €200–€600. OBM hardware/software (PM sensor, additional NOx sensor, data logging, cybersecurity) can add €30–€100 hardware plus engineering/validation. Higher precious‑metal loadings to guarantee 200,000 km durability can swing costs substantially with commodity prices.
Packaging effort, heat shielding/insulation, and warranty reserves increase overhead. Net per‑vehicle impact commonly falls in the €200–€1,000 range depending on baseline and powertrain, with the steepest relative burden on small diesels and low‑cost PFI gasoline. Implications: Reliability improves for emissions hardware (designed for 10‑year life), but serviceability must address sensor drift and filter ash loading. Emissions are cleaner in the real world, especially ultrafine PN and cold‑start NOx, and tampering becomes harder.
Costs rise from aftertreatment volume, precious metals, sensors, and validation, pushing some makers to drop diesel from small segments and to migrate PFI gasoline to GPFs or mild hybridization to cut cold‑start load. Drivability remains strong if calibrations manage backpressure and warm‑up strategies; slight fuel penalties are possible, but torque response is maintained with careful thermal and boost control.
