The recent banning of older diesels from the centre of Stuttgart and the introduction of charges for such cars in central London lead us to believe that diesels are being slowly exorcised from city centres.

But what if your diesel produced no emissions at all in town? What if it could drive into and cruise around the London ULEZ without so much as a particle of particulates issuing from its exhaust?

A plug-in diesel hybrid appears to be the answer to these questions: it delivers the zero tail-pipe emissions of a fully electric car in town, and the outstanding range, fuel consumption and power delivery of a modern diesel in the countryside. The E300 DE I’ve been driving does indeed answer a lot of questions. It’ll cover around 24 miles on electrons alone, hit 62mph from rest in under 6sec, and you don’t need to try that hard to get a genuine 50mpg from it. It is very clever, and in normal use, the flaws are very hard to spot. But flaws there are: you lose a sizeable chunk of the boot to the batteries and the weight gain is close to 400kg. So the handling is more ponderous and if all you’re going to do is slog along the motorways, the same engine in an E220d without all the electrics will be more frugal, whatever the official figures may claim.

So, like all even partly electric cars, this too is a niche model likely to appeal only to those whose lifestyles it fits very precisely.

Mercedes-Benz 300 de EQ Power AMG

Price £50,195
Engine 2.0 litres, 4 cylinders, turbocharged
Power 302bhp (combined output)
Weight 2060kg
Power to weight 147bhp per tonne
Transmission nine-speed double clutch, rear-wheel drive
0-60mph 5.9sec
Top speed155mph
Economy 166.2mpg
CO₂ 41g/km
Verdict Clever, but only for the few