Organisations running heavy-duty automobiles (HDVs) are met with larger issues when it comes to the current Clean Air Zones and the Ultra-Low Emission Zone; specifically the requirement to pay a substantial daily amount for non-compliance. Retrofitting these automobiles can make them legal while at the same time saving on the expenses of purchasing a new compliant vehicles, such as a refuse collection vehicle.

If you are reading this article, you may be a manager of a fleet service or just a person who is facing the same obstacle and is looking for a cheaper yet durable way of making your vehicles legal and compliant with the new policies and regulations. Well, worry not! There is an easy and correct way to avoid the Clean Air Zone fees – maintain your fleet with a retrofit solution.

Picture of retrofit SCR system installation

A Routemaster bus is retrofitted with a new ULEZ compliant exhaust at Clapton Bus Garage. 14/2/2019


While automakers are reducing the environmental effect of diesel engines, new emission requirements mean that we are expected to see intensified demands for tighter vehicle emission controls. Instead of replacing a vehicle, retrofitting a system involves reducing the emissions from older vehicles by installing emission control systems, restoring engine parts, or upgrading existing systems. Any retrofitting options could remove 99 percent of nitrogen oxides in diesel exhausts.

A substantial majority of pollution comes from road transport, both personal and public, and is more severe in heavily crowded urban areas. Modeling by local councils and Defra has demonstrated that it is only through establishing Clean Air Zones (CAZs) that urban areas will comply with pollution levels in the shortest period, which is the difficult task laid down, following lawsuits filed by Client Earth against the United Kingdom Government.

Unfortunately, new car procurement cycles would not carry low-emission cars onto the roads fast enough to clean up the air we all inhale within the timeline required. Taking into account that new data indicates that about 40,000 individuals throughout the UK are dying prematurely caused by air pollution, local officials need to move urgently to prevent further legal cases and/or fines.


There are three choices for businesses: pay the penalty, bypass the zone; or operate a compliant vehicle. Only a compliant vehicle  would help improve pollution rates though.

Whether or not retrofitting is the right solution depends on the situation of the fleet. Having the new Euro VI technology is ideal, and will save more money the more the fleet travel in CAZ and ULEZ. Penalties will be large especially for those who travel everyday in the zones..


If you are looking for an amazing retrofit solution,  check out our RETROFIT SOLUTIONS page.

Excalibre Technologies is the successful UK companion of industry-leading, Proventia Oy. Proventia NOx BUSTER® City is a retrofit option for that allows Euro 3, 4, or 5 vehicles to follow Euro 6 requirements.

Proventia is headquartered in Oulu Finland and is a pioneering leader in the development of the retrofit solution and OE pollution control systems. The networks have complete TFL and CVRAS clearance to ensure compliance with Ultra Low Emissions Zones (ULEZ) and Clean Air Zones throughout the United Kingdom. About 1,000 networks have already been completed throughout leading bus operators in London.

Proventia’s UK affiliate, Excalibre Tech, has a community of highly qualified local engineers to build and operate the systems with 24-hour services open to all clients. After installation, Excalibre Tech offers a robust operation and repair package including their advanced truck and bus DPF cleaning service..  Solutions include everything from implementation to after-sales, including repair and support options, reassuring prospective future fleet managers with retrofit solutions.