The fuel efficiency of heady-duty vehicles (HDVs) in Europe hasn’t improved in the last 10 years.

That’s according to a new report by the International Council on Clean Transportation.

It states the efficiency  of HDVs has remained “relatively constant since the early 2000s”.

It adds although HDVs represent only 4% of vehicles on the road, they are to blame for 30% of transport CO2 emissions.

The report found the key HDV types in the EU are tractor-trailers and rigid trucks – which are responsible for the bulk of sales and fuel consumption in the sector.

Seven member states (Germany, Poland, Spain, France, United Kingdom, Italy and The Netherlands) are responsible for around three-quarters of the EU’s heavy-duty CO2 emissions.

It went on: “Assessing sales trends during the past 10 years illustrates the trend in the EU is towards heavier vehicles and larger engines, more similar to those being sold in the US.”

Volkswagen recently revealed almost 1.2 million cars in the UK have been affected by its diesel emissions scandal.