A Responsible and Cost-Effective Solution to Green Coach Fleets: CRMT Completes  the World’s First Conversion of a Euro VI Diesel Coach to BioGNV 

CONTEXT: RESPONDING TO THE CLIMATE EMERGENCY WITHOUT DISCARDING  EXISTING VEHICLES 

In light of the decarbonisation goals and the requirements of Low Emission Zones (LEZ),  the Pays de la Loire Region and Transdev Pays de la Loire aimed to take a step ahead.  Their ambition: to adapt existing vehicles to meet today’s environmental challenges  without systematically resorting to purchasing new ones. 

This pilot project was designed to test the relevance of BioGNV retrofit as a concrete  lever for energy transition—offering a solution that combines greenhouse gas reduction,  cost optimisation, and the reuse of existing assets. 

BioGNV retrofit involves converting a vehicle originally equipped with a Diesel or petrol  engine into one powered by a BioGNV engine (Bio Natural Gas for Vehicles). This  solution enables rapid action to green existing fleets while avoiding the environmental  cost of manufacturing new vehicles. 

TECHNICAL CHALLENGE: CONVERTING A DIESEL COACH TO BIOGNV

CRMT, a specialist in alternative powertrains and emission reduction, was entrusted  with the project. The objective: convert an IVECO Crossway Euro VI Diesel school coach  to run on BioGNV, while maintaining its performance and operational comfort. Several key steps marked the transformation:

• Installation of a CNG tank providing a range of over 300 km, 
• Deployment of a full CNG fuel system, 
• Complete replacement of the Diesel engine with a CNG power unit,
• Electronic recalibration of the gearbox, 
• Integration of a specific depollution system, 
• Replacement of the Diesel auxiliary heater with a CNG-compatible version.
• The conversion kit was designed to incorporate as many IVECO components as  possible, allowing operators to retain access to the manufacturer’s after-sales  network. 

AN INNOVATIVE PROJECT INAUGURATED IN SARTHE 

This unique retrofit was made possible thanks to the support of the Pays de la Loire  Region, which funded part of the project, Transdev Pays de la Loire, which provided the  vehicle, and GRDF, a committed partner from day one. 

The project culminated in an inauguration on April 11, 2025, in Sillé-le-Guillaume,  during a stage of the Région Pays de la Loire Tour. 

Madame Christelle Morançais, President of the Region, praised this innovative initiative  at the official unveiling of the vehicle, in the presence of teams from Transdev, GRDF and  CRMT. 

The vehicle will soon enter service in the Sarthe region. 

CLEANER MOBILITY WITH A STRONG ECONOMIC ADVANTAGE

The retrofit developed by CRMT delivers measurable environmental performance: • -70% reduction in nitrogen oxides (NOx), 

• -80% reduction in fine particles (diameter > 23 nm), 
• Significant reduction in CO₂ emissions, 
• Half the cost of a new vehicle, 
• Range over 300 km, tailored to school routes, with flexible refueling options, 
• Compliant with LEZ and Crit’Air 1 regulations, ensuring wide geographic  accessibility. 

Operationally, the vehicle’s downtime is limited to just two weeks, enabling a  quick return to service. The kit comes with a 2-year warranty, and installation  can be carried out either regionally or on-site, depending on operator needs. 

A SCALABLE BIOGNV RETROFIT SOLUTION 

The success of this operation paves the way for broader deployment. CRMT now offers a turnkey retrofit solution for local authorities and transport operators. A version  compatible with Euro V vehicles is also available.