Hi Today I am suggesting the Subclass DLC. These DLC would add different subclasses such as for the class 375 it could include the 375/6 /7 /8 The cost would be anywhere from £4.99 to £7.99.
We do technically have sub-classes in the US, but now-a-days it is really more just variation based on each railroad's preference. an SD40-2 could be considered a sub-class of the SD40. A C40-8W, C40-8, B40-8W and B40-8 could all be considered sub-classes as they are all identical, except for the B's having 4 axles and the C's having 6 axles, and the W's having wide cabs. however because of external differences, a pack like this would be very close to having multiple locos pack into one. $10 isn't even the cost of one loco DLC, much less the cost of multiple locos
Not to mention the Dash 8 40 CM, the Dash 8 41CW or the Dash 8.5 40CW etc.. There are almost endless order variations and rebuilds among American railroads. It's almost impossible to keep track. I doubt that DTG would model even a small fraction of these variants.
There are subclasses in Germany, but the differences are mostly concerning the electric equipment and the possibility of operation in different systems (for other countries). The DB and MRCE 185 in TSW are different subclasses for example. Needless to say, I highly doubt this type of DLC would sell well. Especially with the recent discussion of players wanting completely new rolling stock (see Br 112 vs 143 discussion). It‘s a bit different if we go back to older locos - there are sometimes more substantial differences, but as a German vintage route only exists in dreams for now, that point is rather irrelevant.
The trouble is adding subclasses may not provide enough 'fresh' gameplay to keep people entertained given most subclasses only add minor visual differences without any real difference to the driving experience. There's also the problem where the more casual 'gamer' doesn't know the differences so potentially limiting the audience. Where this would come in use though would be adding more services to routes, such as a potential Class 377/6 adding additional suburban stopping services to the upcoming BML or a Class 387/1 adding Thameslink services. Otherwise I would say it would be better to focus resources on new trains rather than duplicating existing ones.
These reasons are all very fair, the point on lack of gameplay is why I priced it at a lower price (4.99-7.99). As AirbourneAlex said some subclasses on British trains add completely different services. The intention was to add more variety to routes in what you can drive/see