I'm always up for a motoring adventure, and my first experience of the new Mercedes C-Class was certainly that. Rather than having the C 250 BlueTEC Sport delivered to me, as is the normal way of things, I collected it from the company's UK HQ in Milton Keynes last Wednesday and returned it 43 hours later in the early hours of Friday morning, having spent fifteen of those hours driving it to and from Amsterdam. This is a car I think I may say I now know reasonably well.I have avoided reading anyone else's review of the car before starting to write this one, but I've heard other journalists say they consider it a thing of wonder. I had my doubts about this to begin with, perhaps partly because I was feeling grumpy about the traffic on the lower reaches of the M1 but also because it didn't seem to ride at all well.It didn't take long to work out what the problem was. The Sport runs on firmer springs than other C-Classes and rides 15mm lower. It also has a five-mode Agility Select system which at this point was set to Comfort. That might work on other versions, but it's not right for this one.The one to pick - easy to remember because it has the same name as the car - is Sport, which firms up the damping nicely. So does Sport+, but it makes the seven-speed automatic gearbox too eager to change down and too reluctant to change up on a motorway cruise. I never found a setting that coped well with sharp bumps.That gearbox (there's no manual alternative on this car) is controlled, in normal Mercedes fashion, by what looks like a stalk just behind the steering wheel. It's quite a good feature, though there was a moment of confusion when I accidentally selected reverse instead of indicating left. The electronics immediately realised what kind of driver they were dealing with and prevented what would have been a disastrous shift from taking place.The engine is a 2.1-litre diesel producing a maximum of 201bhp, with more than half of that already available from just 1600rpm. There's more than enough performance for a continental run, even when you're under pressure to reach a hotel in one direction and a tunnel in the other.My only criticism of the engine is that it's a bit grumbly. Mercedes might work a bit harder on keeping the noise levels down. But my disappointment about that was made up for by the fuel economy.The C 250 ran for 757 miles on a single tank (at an average, according to the trip computer, of 56.5mpg, which I didn't check but can easily believe) and although by that time warning lights were telling me I should head for the nearest diesel purveyor as soon as possible I reckon I could have got to 800. With more care and a lighter right foot I don't think 900 would be out of the question.I tend to need a stop to stretch my legs on a long trip, but I could do three and a half hours solid with no problem in the C 250. The seats are very good and there's plenty of room up front, though there's less headroom in the back and not much space under the front seats for rear passengers to put their feet.Generally, though, the interior is a comfortable place to be, and an attractive one too. The minor controls are smart, particularly the ones on the doors, though a more consistent design language throughout the car would be better. The graphics on the TFT digital instrument display are beyond criticism.So too are the ones on the central 8.4" multimedia display screen, part of the £1495 optional COMAND Online system. This can be controlled in various ways, some of which take a bit of getting used to. The most modern is to use the thing that looks like a giant mouse, whose upper face can be used to draw the letters in the name of wherever you want the satnav to lead you to. It's not my favourite method, and is always going to be a problem for right-handed UK drivers because it's on the wrong side for us.Like systems I've come across in other cars, this one has difficulty with foreign place names when it's giving you directions in English. The syllables seem to have been recorded separately and spliced together, leading to several situations which made me burst out laughing. When my attention was drawn to a signpost for an industrial complex near Antwerp I thought the poor woman giving the instructions was having a stroke.There's 480 litres of space in the boot, exactly the same as you get with the slightly longer Audi A4 and slightly shorter BMW 3-Series. It's almost as if the premium German manufacturers have made an agreement to offer the same amount of luggage room, though I doubt this is the case.As with saloons in general, the boot opening is nothing like as large as it would be in a hatchback. The C-Class isn't available in that form, so if you need to load awkwardly shaped objects you're going to have to wait for the estate to come along later this year. Engine 2143cc, 4 cylinders Power 201bhp Transmission 7-speed automatic Fuel/CO2 64.2mpg / 113g/km Acceleration 0-62mph: 6.6 seconds Top speed 153mph Price £34,015 Details correct at publication date