Everything You Need to Know About Euro 6

The Background
It’s not a secret anymore that cars burning fuel are emitting toxic gases and particulate matter, especially heavy diesel-powered vehicles that haul people around and supply the supermarket next to you.

These tailpipe emissions have been found responsible for sickening the people living in urban environments and also “help” with the climate change. Reasons for which most countries have adopted standards, forcing automakers to build vehicles that emit less and less harmful gases.

Speaking of emissions, the key constituents are NOx (Nitrogen Oxides), PM (Particulate Matter) and CO (Carbon Oxides).What are the Euro regulations?
About 20 years ago or so, diesel engines were the most polluting ones because of their working principle, long times to reach optimum temperatures, the inferiority of diesel fuel as well as the lack of depolluting systems.

Therefore, the European Commission decided to limit the effects of diesel engines on the environment by creating the Euro legislation. The first one was called Euro 1 and has been applied in 1993, creating several emissions classes – you get one for passenger cars, three for light commercial vehicles and one or two for heavy commercial ones (trucks and busses).

To make yourself an idea, here’s how the Euro 1 standard was limiting the three car categories:

• passenger cars: CO 2.72 g/km || PM 0.14 g/km
• light commercial vehicles (≤1,305 kg): CO 2.72 g/km || PM 0.14 g/km
• light commercial vehicles (1,305 – 1,760 kg): CO 5.17 g/km || PM 0.19 g/km
• light commercial vehicles (1,760 – 3,500 kg): CO 6.9 g/km || PM 0.25 g/km
• trucks and buses (<85 kW): CO 4.5 g/kWh || NOx 8 g/kWh || PM 0.61 g/kWh
• trucks and buses (>85 kW): CO 4.5 g/kWh || NOx 8 g/kWh || PM 0.36 g/kWh

Note that the first two categories were lacking a limitation for NOx emissions and that trucks/buses standards were defined by energy output and not driving distance, so they are not comparable in any way.How did it evolve?
About every four years, the Euro standards got harsher with the automakers. In 2000, the new Euro 3 also introduced an NOx limit of 0.50 g/km for passenger cars and light commercial vehicles, while also cutting down CO by almost 50% and PM by about 20%.

The last regulations introduced were dictated by the Euro 5, which took effect in September 2009 and dropped the emissions to the following standards:

• passenger cars: CO 0.5 g/km || NOx 0.18 g/km || PM 0.005 g/km
• light commercial vehicles (≤1,305 kg): CO 0.5 g/km || NOx 0.18 g/km || PM 0.005 g/km
• light commercial vehicles (1,305 – 1,760 kg): CO 0.63 g/km || NOx 0.235 g/km || PM 0.005 g/km
• light commercial vehicles (1,760 – 3,500 kg): CO 0.74 g/km || NOx 0.28 g/km || PM 0.005 g/km
• trucks and buses: CO 1.5 g/kWh || NOx 2 g/kWh || PM 0.02 g/kWh

Note that heavy vehicles (trucks and buses) are now contained in one category.What are the Euro 6 changes?
Euro 6 is the next step in the regulation, mostly aimed at limiting the average CO2 emissions bellow 130 g/km across a car company’s range. In fact, it has already been adopted for trucks and buses since December 2013, now following to be also applied to passenger cars and light utility vehicles.

It can be somehow looked at as an improved version of the Euro 5, since it comes with some limited changes throughout the range as you’ll see here:

• passenger cars: NOx 0.08 g/km
• light commercial vehicles (≤1,305 kg): NOx 0.08 g/km
• light commercial vehicles (1,305 – 1,760 kg): NOx 0.195 g/km
• light commercial vehicles (1,760 – 3,500 kg): NOx 0.125 g/km
• trucks and buses: NOx 0.4 g/kWh || PM 0.01 g/kWh

Everything else remains as the Euro 5 standard says. Does Euro 6 affect me?
As a car buyer, you won’t feel such a big difference. The most you might feel is a price increase for new Euro 6 compliant cars, since automakers have to fit them improved depolluting systems.

Those who will be really affected are fleet operators; the larger the fleet, the larger the overall price hike they need to live with, because that 130 g/km limit won't be reached without replacing the old vehicles.

For individual use, you can still buy a car that emits over 130 g/km, but you will pay more tax for it. However, it makes more sense to invest in a new Euro 6 one now for two reasons: first, because you get the latest technology, which will also grant a lower fuel consumption (since that and emissions are close related) and secondly, you’ll cope better with the even more stringent 2020 regulations if you plan to keep the car for longer.How the automakers will make vehicles Euro 6 compliant?
Well, there are three main methods to make a diesel engine emit less:

• Exhaust Gas Recirculation (EGR) – which cuts NOx but can increase fuel consumption
• Selective Catalytic Reduction (SCR) – which cuts NOx as well by using an additive, but can increase the vehicle weight and also add a new consumable
• Diesel Particulate Filter (DPF) – which cuts particulate matter but adds up more maintenance work and vehicle weight

These technologies can already be found on most newer diesel vehicles and are usually used in a combination. You must have heard at least about AdBlue already…

However, along with these, the European Commission has also devised new procedures, tests and specific requirements in order to achieve the new standards.

So automakers will need to pay closer attention to things like evaporative emissions and crankcase emissions, test cycles that monitor low ambient temperature emissions and those at idle speed, on-board diagnostic systems and hybrid powertrains.

Another thing to know is that with the introduction of the Euro 6 standard, a new “World Harmonized Test Cycle” has been firstly used for engine certification.Is the Euro 6 standard affecting gasoline-powered cars?
Although the Euro 5 implied some changes in how much exhaust gas
es gasoline cars are allowed to produce, the Euro 6 standard doesn’t come with any changes.

Euro 6 standards for gasoline powered vehicles are currently set at:

• passenger cars: CO 1 g/km || NOx 0.06 g/km || PM 0.005 g/km
• light commercial vehicles (≤1,305 kg): CO 1 g/km || NOx 0.06 g/km || PM 0.005 g/km
• light commercial vehicles (1,305 – 1,760 kg): CO 1.81 g/km || NOx 0.075 g/km || PM 0.005 g/km
• light commercial vehicles (1,760 – 3,500 kg): CO 2.27 g/km || NOx 0.082 g/km || PM 0.005 g/km

So, as long as you’re not a fleet owner that needs to bring down the average emissions level by purchasing newer cars, you shouldn’t have any problems. All you need to remember is that Euro 6 cars will consume less fuel than Euro 5 ones (not applying to gasoline cars since the regulations remained the same), the standard becomes obligatory in September 2015 and you can still buy cars with over 130 g/km as long as you’re willing to pay more tax.