Voyager 2093
Member
The 170 was a technical improvement on the 168- which basically a pre-privatisation design. The 171 merely differs in coupler- the 170s have a coupler compatible with Sprinters, whilst the 171s are compatible with 377s. 172s are technical development further of the 170- lower speed, and one batch will have a corridor connector.
The 221 IS the tilting version of the 220.
Some of the class numbering as to whether different versions of trains count as sub-classes or "full" classes can be somewhat arbitrary.
Depends on which sub class of 168 your talking about. Correct me If I'm wrong but 168/1 and 168/2 are much better accelerators than 170s on a whole and they are faster than 170s, well 6mph faster.
