As far as I understand, the Avro RJ is a newer version of the BAE 146? What are the exact differences?
The main difference between the Avro RJ and the BAe-146 is the engine- The RJ has Honeywell LF 507-1F, which is developed from the Lycoming ALF 502R-5 used in 146. The main difference between the engines is that the 507 has more LP turbine stages (2 Vs 1), sightly more thrust (31.5 KN Vs 31 KN) and has a single-channel FADEC with hydro-mechanical backup.
Visually, the 146-200 has a small triangular bump in the rear fuselage to prevent tailstrike, while it isn't there in RJ85.