Euro VI and Euro 7: what the emission classes mean for operators

The emission class on a truck’s specification sheet is not a trim level. It is a legal category that decides whether the vehicle can be registered at all, how long the manufacturer stays responsible for the emission system, and increasingly what the truck costs to move down a road. Euro VI has governed European heavy vehicles since the start of the 2010s. Euro 7 replaces it at the end of this decade, on dates close enough now to belong in fleet replacement planning.

Roman numerals for trucks, Arabic for cars

The two systems are genuinely different regimes that happen to share a name. Heavy-duty standards use Roman numerals — Euro I through Euro VI — and are applied to the engine, tested on a dynamometer, with limits expressed in grams per kilowatt-hour. Light-duty standards use Arabic numerals and are applied to the whole vehicle, in grams per kilometre.

This matters when reading a spec sheet, because manufacturers do not always keep the convention. MAN publishes Euro 6e for the TGX and Mercedes-Benz publishes the same for the Actros L; on a heavy vehicle that means Euro VI step E. Others publish no sub-step at all: DAF states only Euro 6 for the XG+, and Scania does the same. Where a maker declines to name the step, the honest reading is that the step is not published, not that it is early.

What Euro VI actually requires

Euro VI comes from Regulation (EC) No 595/2009, with the test procedures set out in Regulation (EU) No 582/2011. Approval is against two world-harmonised engine cycles, the steady-state WHSC and the transient WHTC.

For a compression-ignition engine the ceilings are 0.40 g/kWh of NOx on the WHSC and 0.46 g/kWh on the WHTC, 0.01 g/kWh of particulate mass, and a particle number limit of 8.0×10¹¹ per kWh on the WHSC and 6.0×10¹¹ on the WHTC. Carbon monoxide is capped at 1.5 and 4.0 g/kWh respectively. Reaching those numbers is why every Euro VI diesel truck carries selective catalytic reduction, a particulate filter and exhaust gas recirculation, and why urea consumption is a real line in the operating budget rather than a rounding error.

Euro VI also introduced on-road testing with portable measurement equipment — the point at which the standard stopped being a purely laboratory exercise.

Steps A to E: the limits stayed, the testing hardened

The letters after Euro VI cause more confusion than anything else in the system. They are not tighter tailpipe limits. The ceilings above are the same from step A to step E; what changed is how hard it is to stay under them.

Step D, from September 2018 for new types and September 2019 for all new registrations, cut the power threshold for on-road measurement from 20% to 10%, which pulls low-load running into the assessed window. Step E, from January 2021 for new types and January 2022 across the board, added cold-start emissions to the on-road evaluation with a 30°C threshold and brought particle number into the portable measurement.

The operational consequence is easy to miss. A step E engine has to control its emissions in exactly the conditions that are hardest for aftertreatment — cold mornings, short runs, low-load urban work — where an earlier step was effectively unmeasured. That is one reason a truck’s duty cycle tells you more about the state of its emission system than its odometer does.

Euro 7 and the two dates that matter

Regulation (EU) 2024/1257 replaces the Euro VI framework, and for heavy vehicles it applies from 29 May 2028 for new types of M2, M3, N2 and N3 vehicles, and from 29 May 2029 for all new vehicles in those categories. Small-volume manufacturers get until 1 July 2031. Cars and vans move earlier, from 29 November 2026 for new types.

Two practical readings follow. A truck type-approved before May 2028 can still be built and registered as Euro VI up to 29 May 2029; after that date it cannot be newly registered. And trailers are inside the regulation for the first time — categories O3 and O4 appear alongside the tractors, on the same dates.

What actually changes in the numbers

For buses and lorries, Euro 7 sets 200 mg of NOx per kWh in the laboratory cycles and 260 mg/kWh in real-driving conditions, against the 400 mg/kWh Euro VI allows on the WHSC. Particulate mass falls to 8 mg/kWh, and particle number is capped at 6.0×10¹¹ per kWh in the lab and 9.0×10¹¹ on the road.

Three structural changes matter more than the halving of NOx. Real-driving emissions now carry their own explicit limits rather than a conformity factor bolted onto a laboratory number. Particle counting moves to PN10, which captures smaller particles than the PN23 measurement used under Euro VI. And nitrous oxide, which Euro VI did not regulate, gets a mass limit of 200 mg/kWh, alongside a 60 mg/kWh ceiling for ammonia; both are slightly higher on the road.

Durability: the change with the longest tail

Under Euro VI the useful-life period for an engine in an N3 vehicle above 16 tonnes is 700,000 km or seven years, whichever comes first. Euro 7 keeps the distance and more than doubles the time: a main lifetime of 700,000 km or twelve years, followed by an additional lifetime running to 875,000 km or fifteen years, during which the gaseous limits are relaxed by a durability multiplier of 1.2.

For anyone buying second-hand this is the most consequential line in the regulation. The manufacturer’s obligation for the emission system now stretches across the second and often the third owner of the vehicle. A Euro 7 tractor at 600,000 km is still inside its main lifetime, not past it.

The truck reports on itself

Euro 7 requires on-board monitoring on M2, M3, N2 and N3 vehicles that registers actual NOx, ammonia and particulate emissions in service and detects exceedances of at least 2.5 times the applicable limit. The system communicates through the OBD port for roadworthiness testing under Directive 2014/45/EU and roadside inspections under Directive 2014/47/EU, and anonymously over the air for type monitoring. It triggers a driver warning when emissions are significantly exceeded, deliberately without stopping the vehicle mid-journey. The monitoring devices cannot be deactivated while the vehicle is in use.

Each vehicle also comes with an environmental vehicle passport, a digital record handed to the purchaser with the truck. Between the two, a roadside inspection stops being a visual judgement and becomes a data read.

Brakes, tyres and the cost of running

Euro 7 is the first standard to regulate emissions that do not come out of the exhaust. Brake particle limits arrive first for cars and vans, with heavy-vehicle limits following a Commission review. Tyre abrasion limits apply from 1 July 2028 for C1 tyres, 1 April 2030 for C2 and 1 April 2032 for C3, the heavy commercial class.

Emission class also reaches the operating account through road charging. The revised Eurovignette framework moves lorry charges towards addressing carbon dioxide alongside pollutant emissions, and phases out time-based vignettes on the core trans-European network in favour of distance-based charging. A fleet’s emission classes have become an input to what its kilometres cost, not only to whether they are permitted.

What to do with this

If you are ordering for delivery in 2028 or 2029, establish which side of 29 May 2029 the registration will fall on, and price the residual accordingly. If you are buying used, find out which Euro VI step the vehicle holds rather than accepting Euro 6 as an answer, because step E carries the cold-start regime and earlier steps do not. And treat an emission warning as what the regulation designed it to be: a prompt for timely repair, not a light to be lived with.