The trees may never clap their branches and cheer as you drive past in one of these new-age 'improved efficiency' cars, because it's common knowledge that all cars damage the environment. Yet, ones like the new Mercedes-Benz C180 K Blue Efficiency could make it fractionally easier to do less damage if you drive them efficiently.

I don't want to bore you with the long list of things that Merc did to make this car more efficient, except to say that it is 32kg lighter and a bit more aerodynamic, for starters.

The previous 1.8-litre engine has been replaced by a smaller 1.6-litre unit — though increased supercharger boost means that power and torque output is unchanged. A more efficient power steering system and revised gear ratios further aid the efficiency quest.

Now, how does all this work in the real world? Marginally, at best, and that's if you drive it like a stoned granny. Well, it takes a lot more skill than that, and my best shot at an economy run procured decent results. This entailed doing all I could to coax the automatic gearbox into changing up at low revs, using every bit of momentum to my advantage and plodding along at the speed limits.

According to the on-board fuel measuring devices, I managed to get consumption to average around 6.3 litres per 100km on a quiet freeway at 100km/h. In average traffic conditions in the urban jungle, I averaged between nine and ten litres per 100km, which is not bad for a car in this category.

Especially considering that I was driving the automatic model, which seemed a bit temperamental, at times holding the gears for a little too long even when I was lifting off just above 2000rpm. Using the manual mode became more a chore than anything else, defaulting back into 'drive' after fourth gear and then needing to be reactivated with a down-change every time the car slowed down.

You can't go wrong with force-feeding at altitude

Of course, throw in some enthusiastic driving and all of this efficiency goes down the toilet, but the C180 K does leap off the mark with vigour and got us from standstill to 100km/h in a shade under ten seconds. You can't go wrong with force-feeding at altitude. Unfortunately, the gearbox was not willing to play along when we did the overtaking acceleration test and those times were below expectation.

Depending on how you drive, this car could offer a good combination of performance and economy and, hewn from the latest C-Class mould, handling is brilliant too and the ride quality is certainly supple enough.

Style is another feather in this car's cap; it has a sporty and ambitious thing about it, but won't offend conservative camps either.

Jump inside, however, and the latest C-Class niggles are still there. The jumbo steering wheel comes straight from a bus; the dashboard looks like a 1980s throwback; and the seats are hardly cushier than cardboard and offer as much support as a hammock in a blizzard.

All of which seems rather wrong when you consider that the C-Class is priced above the opposition. With a better interior, this car could be a notch short of brilliant.

Which Aston are you? Aston Martin stirs the emotions. Our overview will help you find a model that fits your mood.

Texting twits? Think you're capable of using a cellphone while driving? Watch this video and think again.

My van can The Materia is not what it seems to be and is deceptive in many ways, Philip Devine discovers.