Diesels face stricter CT tests in pollution crackdown

More than 15 million diesels will face extra tests targeting pollution, cutting emissions to almost the same level as when the vehicles were new.

Only post-2005 vehicles – meeting Euro 4, 5 or 6 – are affected and cars need a test from four years old.

Test centres expect a rush of owners trying to beat the test as a pass is valid for two years. Petrol cars will also face tests on emissions of carbon monoxide and CO2, unburned hydrocarbons and nitrogen oxides.

The moves follow May’s change to bring France into line with EU road safety standards. Some diesel drivers could face bills of up to €4,000 for work – especially those with défapée cars with the particulate filter taken out.

Renewing this or an exhaust gas recirculation (EGR) valve is expensive, but the vast majority will gain a pass.

Rémi Courant, quality control head at major CT chain Dekra, said: “The aim is not to put cars off the road but to cut pollution by reducing emissions to near the level when the car was new.

“If vehicles are well maintained, they should pass with no problem – and the test should cost only a few euros extra.”

Vehicles doing only short runs in town can soot up emissions filters, but drivers could avoid this by doing longer journeys.

Chemical treatments for the fuel tank are available but some garages offer a “green” décalaminage, where hydrogen is injected into the engine to “burn” soot. Elsewhere, garages offer a check and clean-up décrassage for about €50. Fabrice Godefroy, of Diéséliste de France group, said tighter emissions rules should mean manufacturers change their servicing routines to do more to cut emissions.

Some owners may also opt out and plump for a new car via the state prime à la conversion that gives up to €2,500 towards a low-polluting car, with manufacturers adding incentives of several thousand more.

Diesels have much better fuel consumption than petrol but are better suited for high-mileage use.