RDE vs RDE2 - Real Driving Emissions Testing Explained

Published Date: 28th Sep 2020

What Does RDE stand for?

RDE stands for Real Driving Emissions, RDE testing was introduced in 2017 for new cars because the existing laboratory emissions tests were found to be unrealistic when compared with real world driving. RDE is part of the EURO 6 standard and testing was made mandatory in 2019.

Close up of car exahaust

Under lab testing a petrol or diesel can emit up to 80mg/km of nitrogen oxide (NOx), this is particularly relevant to diesel cars which have been found to emit much higher levels of nitrogen oxide under real driving conditions.  These emissions contribute to environmental pollution especially in busy city centres and areas where there is heavy traffic.

What VED Supplements Are Applicable for Non-Complaint RDE Diesels?

The government announced back in 2017 that there would be a new first year levy on diesels registered from April 2018 onwards. The new levy meant that new diesels would be subject to an additional VED tariff based on the tax band above for the first year.

Are Any New Diesels Exempt From The First Year Supplementary VED Tax?

Yes, if your new diesel has passed and meets the requirements of the stricter RDE2 testing then it will be exempt from the first-year additional VED tariff. More and more new diesels are RDE2 ready and the standard will become mandatory for all new diesels registered from January 2021 onwards.

If your car not does meet RDE2 and it’s a diesel then you need to look up your CO2 emissions tax band and be aware of the additional tariff.

What is RDE?

RDE was the first stage of government real driving emissions testing. The RDE nitrogen oxide limit is 2.1 times the lab testing limit of 80mg/km under real driving tests. RDE was made mandatory for all new cars registered from September 2019.

What is RDE2?

ULEZ Sign

RDE2 is the next stage in reducing harmful nitrogen oxide (NOx) emissions in new cars. RDE2 complaint cars will have a ceiling of 1.5 times the lab testing limit of 80mg/km of nitrogen oxide under real driving conditions/tests. The new RDE2 standards will be mandatory for all new diesels registered from January 2021.

ULEZ, Low Emissions & The Benefits Of A New Car

As well as some of the obvious financial benefits of lower tax bands and a cleaner, more economical new car, lower emissions vehicles may be exempt from ULEZ (Ultra Low Emissions Zones) charges when travelling into City Centres and designated areas.

London’s ULEZ zone is set to be expanded in 2021 and many other City Centre’s are following suit or have put plans in motion for their own similar Low Emissions Zones and tariffs.

If you trade in your old car for a new, cleaner vehicle you are of course lowering your carbon footprint, doing your bit for the environment, and helping to improve air quality.