Originally posted by Snowman
As was said before, just because you have 4 cylinders doesn't mean that you are more enviroment friendly or get better mileage.
Look to Honda. All their cars right now are LEV, with the Accords and Civics being ULEV. Also as mentioned, the Insight is SULEV and gets excellent gas mileage.
Generally speaking, four bangers are smaller displacement, get better mileage, and are less expensive in the long run to maintain. The Honda Civic is a four cylinder, and the Accord four is more economical than it's six variant.
The feeling I got from the original post is that the person is looking for some sort of compromise. He wishes Mercedes goodness, but in the most economical and environmentally friendly version. Even the new M112 V-6's in 2.6L format cannot match the mileage of the M111 equipped W202 cars. While the M112 engine is a lower emission engine, it consumes more fuel therefore creating more greenhouse gases. It's a compromise decision.
Compared to ANY SUV bigger than a CRV, a Mercedes four cylinder is a miserly automobile indeed. Even the six, and some V-8's are economical compared to a full sized SUV.
Doing the math on carrying capacity? Hhhmm. A C230 driving in city traffic get's about 9.0-9.5L/100km's in "normal" urban driving. My neighbour's Expedition gets about 20L/100km's in city driving when taking it easy. We could drive TWO C230's carrying 8-10 people and use LESS
fuel than the Expedition. And most of the time, that behemoth is carrying one person, and it's capacity is wasted. If you need to carry 7 people ALL the time, it might make sense. Using two highly efficient cars allows greater flexibility. We can leave one at home when we don't need it.
A Prius is a good choice, but does not work well for enthusiast drivers. It handles poorly, and lacks many of the safety features of the Mercedes. It is not capable of effortlessly climbing a steep mountain pass or passing a long line of cars. A Mercedes four-cylinder car can do those things. However, for an urban-only car, a Prius would be an excellent choice.
As I said before, just dare to mention that you would actually make a conscious decision to consume less fuel, and be prepared to be slammed.