Strange behaviour

When I had my Honda Preludes I used to drive with the fastest flowing part of motorway traffic. I was careful, observant and only occasionally the fastest driver of any group (much better to let someone else attract the attention of the Police). Long journeys always felt shorter and more pleasant when I was making progress. From time to time I was irritated by those who would not do as I (try to) do and keep left when not overtaking but everyone suffers because of them. Times and circumstances changed and the Prelude was replaced by my first Citroen BX, the 1.9 litre automatic. It was a long-legged car, typically French in that it gathered speed slowly but felt as though it could sustain high speeds all day. Respect for the car's great age and the lower level of performance available caused me to drive more slowly in the Citroen than I did in the Honda. Journeys took a bit longer but it was something I (grudgingly) accepted. Now I have a 1400cc Citroen BX which is slower than the old BX. As a result my cruising speed on the motorway has dropped considerably. In the old BX I'd keep the speedometer between 70 and 80mph, in the new car it is more likely to be 60-70. Not only does this have an impact on the time it takes to make a long journey but I have noticed something new about the so-called Middle Lane Owners Club. While I am passing a convoy of slower I will try and do it as quickly as possible but there are drivers who will sit right on my tail, clearly wanting to go more quickly, even when there is a clear overtaking lane to the right. Only once I pull over to the left do they drive past but they don't pull over into the clear left-hand lane.