We have choosen the S 431 DT double-decker as a counterpart to the recently described competitor of Neoplan (MAN), although it only optical belongs to the 500 series and it has also given him long before 2013. The two are very similar in motorization, dimensions and also in price.

Unbelievable, for what one can need the basement, except for passengers. Case of two drivers one finds here a place to sleep on the long-haul route. You can order the bus without a toilet, which is therefore not included in the basic price.

Of course, there can be built-in next to a bistro, a galley which can serve, inter alia, meals, for guests sitting around a longitudinally arranged table. What a bus with high floor does not need is the low-floor principle for the lower gear, relief for the accessibility for the disabled mandatory to introduce in 2020.

Good that the double-decker is slightly shorter than the longest 500, because in terms of luggage space it draws the short straw. So many a suitcase for rear will be ordered with. Whether then and at all the S 431 DT achieves the fabulous drag coefficient of 0.33, we leave open. Maybe the 'smaller' in-line six-cylinder becomes still stronger and drives even the really big sometime.

In any case, efforts are being made everywhere to prove a certain saving even with Euro 6 engines. This applies even to the cheaper AdBlue, in which one partly will have fallen clearly below the 5 percent limit. But the changes for achieving this rugged NO_x limits are already clearly visible when opening the engine compartment (Figure 9). 12/14