A few years ago, Nottingham-based lift installation and servicing firm Morris Vermaport decided to provide petrol-electric hybrid cars for its service engineers to use, in a bid to align its fleet with the company’s commitment to minimise emissions and fuel consumption and operate as sustainably as possible.

Photographs on the company’s website suggest these cars were Toyota Prius, but the specific model doesn’t really matter.

What did matter, according to Andrew Waddell, the firm’s operations director, is that company vehicle tax rates on these cars were prohibitively high — in particular, they were much higher than the tax rates on the Mercedes-Benz Citan vans the firm has now purchased to replace the hybrid cars.

Fuel consumption from the hybrid cars wasn’t exceptional either, when looked at across the vehicles’ full usage cycle, according to Mr Waddell:

“There’s not a lot to choose between the two vehicles in terms of mpg returns – the hybrids are good around town but less so on longer runs, or when fully loaded, which is when the Citan really shows its class.”

To me, it looks like the hybrid cars were an optimistic, well-intentioned choice that didn’t quite work out — although it might have done had the tax regime been more favourable. This is an important point because fuel consumption isn’t the only issue here: there’s clear and abundant evidence that diesel emissions are the biggest single cause of air pollution in UK cities, thanks to nitrogen dioxide emissions, which are largely ignored by the EU-led CO2 vehicle taxation regime.

As I discussed recently, there’s an obvious case for changing the vehicle tax incentives away from their narrow focus on CO2 emissions, to a more complete view of pollution. In this scenario, Morris Vermaport might have found that their petrol-electric hybrid cars were more cost effective — and less polluting.