What is RDE2 compliance?

How is the RDE2 test carried out?

The RDE test operates in the opposite way to the NEDC and WLTP lab tests – instead of the engine being taken out of the car and brought to the laboratory, the testing gear is taken out of the lab and brought to the car. 

The kit used is a Portable Emissions Measuring System (or PEMS, because we need another acronym), it hangs off the back of the car and is plugged directly onto the exhaust. It measures NOx and soot known as particulates – both nasty stuff that causes respiratory problems and early death.

The car is then driven on a mixture of roads – town, country and motorway – up and down hill, the results are then calculated using software that makes adjustments for weather and traffic conditions to provide the most accurate results possible. 

Are the RDE2 tests really that much more effective?

In a word – yes. RDE testing has shown cars to produce up to 12 times the amount of NOx gases measured under WLTP lab tests. 

Meanwhile, of the 131 Euro 6 compliant diesel cars tested by real-world testing experts Emissions Analytics back in May 2017, only 15 met their NOX threshold under real world conditions. 

Not only will RDE2 testing give governments a much clearer picture on how much harmful emissions cars produce, it also means we can buy cars confident that they’re as clean and as fuel efficient as they claim to be. 

How does RDE2 affect the VED tax you pay?

In the 2017 autumn budget it was announced that diesel cars that don’t conform to RDE2 emissions standards will be treated as though they sit in the group above for VED (Vehicle Excise Duty). 

For example, an older Ford Focus 1.5-litre diesel produces 118g/km of CO2 emissions so it should qualify for band 111-130g/km road tax of £175 in the first year. But, because it’s not RDE2 compliant, it actually sits in band 131-150g/km and costs £215 to tax in the first year. 

Why is RDE2 important for company car drivers?

RDE2 has only been a requirement for newly designed cars since January 2020 but doesn’t come into force for all newly registered cars until January 2021. But why does this matter if you’re a company car driver? 

Well, RDE2 cars qualify for a 4% tax break in the first year – none RDE2 diesels are calculated as if they sit in the tax band above – that could save you a lot of money.  

Compare the Ford Focus 118PS diesel to the Vauxhall Astra 122PS diesel. The latter qualifies for the 4% BIK tax break – you’ll pay a 26% rate versus 31% in the Ford, saving you around £500 in the first year. Significant on two cars that would cost roughly the same to buy outright.