Welcome. I hope you enjoy your Lexus. Lovely car. I am sure you will find vast fuel savings after driving pick up trucks. I know of at least one person who updated from a non hybrid to a hybrid version of the same model and, though their mpg improved, were disappointed that the improvement was not all that great. Perhaps it takes a spell to learn how to get the best out of a hybrid. Keep us informed as to how you get along.
Most hybrids have great fuel economy. The NEDC is just a horrible test for real world results no matter the car. The reported average here for a model is usually pretty close to the EPA combined rating.
Depends on car age, milage, engine temperature, outside temperature, service history etc etc
Lab and real world tests beg to differ with that statement. The diesel should be better on particles because of the DPF, and it might have an advantage on CO, but that is about it.
The Prius emits a fraction of the pollutant limits required for the cleanest EPA bin. Some diesels might qualify for that bin, but no manufacturer is willing provide a warranty for over concerns for emissions as the car ages.
CO2 emissions is purely a factor of efficiency. A diesel could out perform a hybrid on the highway, but most miles are driven under city conditions. Then most people don't want smog in their city.
True, although don't forget older higher mileage petrol engined vehicles (which there are alot of in the US) are responsible for a huge amount of nitrogen oxides too. Did you read the BBC experiment? An old Golf petrol V's a fairly old VW engined Skoda diesel, the Golf's nitrogen oxide emissions were 300% higher than the diesel.