Transport Scotland and Energy Saving Trust are set to end taxi retrofitting grants in just two weeks' time.
According to retrofitting experts there is no further news of future funding rounds to help drivers make their taxi engines cleaner and meet EURO 6 emission levels.
The Scottish Government brought in the new fund in 2019 to help commercial organisations, including taxi drivers, impacted by the introduction of Low Emission Zones.
A spokesperson from Cybrand, a UK retrofit and emissions solutions firm, warned: “We’ve heard this morning that the funding for Euro 6 retrofit in Scotland will be closing to new applicants on 21 February.
“No news at the moment if there will be any further rounds of funding.”
Several major councils across England and Scotland have and continue to offer grants to taxi drivers willing to upgrade the cabs.
Cab drivers could make the switch to greener cabs for as little as £1,300 in some cities.
Aside from buying a new Zero-Emission Capable (ZEC) taxi, retrofitting existing cabs to meet Euro 6 compliance standards is seen as one way to eliminate daily charges and future proofing licensed taxi.
The accreditation required to become exempt from emission zone fees within the LEZ or CAZ is known as Clean Vehicle Retrofit Accreditation Scheme (CVRAS) and is administered by the Energy Saving Trust. Cybrand are the only approved installer with this certification able to offer a retrofit conversion on taxis which doesn’t involve a completely new engine.
On a standard Euro 5 compliant taxi, exhaust gas from the turbocharger passes directly into the combined catalytic converter and diesel particulate filter and from there through the silencer to the tailpipe.
On a retrofitted Euro 6 compliant cab, a new Selective Catalytic Reduction (SCR) system is installed into the exhaust system further downstream. This incorporates a thermo-electric element which helps to bring the exhaust to an ideal temperature to encourage efficient catalytic conversion. Together with the introduction of AdBlue, which is a diesel exhaust fluid, the SCR system reduces NOx down to levels that exceed the requirements of Euro 6.
SCR is beneficial because it reduces NOx by up to 90% and is one of the most cost-effective and fuel-efficient technologies available.