Hybrids might be promoted as the environment’s friends, but if you’re really serious about reducing CO2 emissions, and can’t manage without a car, then what you need is the smallest and most economical car you can find. And this could be it. The Smart CDI diesel is claimed to emit just 88g/km of CO2, the lowest emissions of any current production car. It also returns 86.5mpg on the combined cycle, which makes a Prius (104g/km and 65.7mpg) look profligate.
A diesel Smart? Hasn’t that been around for ages?
In Europe, yes. It was launched alongside the other new-generation Smarts last year, but so far only petrol models have made it to the UK. No other right-hand drive market has shown interest in the diesel, and it’s taken this long to persuade the suits at Daimler to build a right-hooker.
Why are the emissions so low?
Not because of any fancy hybrid drive system: the CDI has just the one motor. It’s the world’s smallest common-rail diesel, with a tiny turbo to boost the 799cc engine’s output to 45bhp at 3800rpm. Tiny capacity, high part-throttle efficiency and light weight (just 20kg more than a petrol Fortwo) keep economy high and emissions low.
Click 'Next' below to read more of our Smart Fortwo CDI first drive
What’s the engine like?
You won’t have any trouble working out it’s a diesel. Despite two-stage injection said to cut noise, the CDI rattles and rasps, though the no-nonsense three-cylinder thrum somehow suits the car. It sounds best when you switch the gearbox to manual and rev the engine hard, though you won’t get 86mpg driving it like that. Even then you’ll struggle to hit 60mph from rest in under 20 seconds, six seconds behind a petrol Smart. It’s quick enough in town, but runs out of puff on the open road.
Sub-100g/km CO2 emissions mean the CDI is exempt from VED, and it’ll be a little cheaper to run than a petrol Smart, particularly in town. It’s a sensible city car, if you can put up with the racket.