Also I thought I would direct you to this piece. This shows you how there is inconsistency in the testing. To give you an example, a CT200h has MPG of 68.9 in the UK. In the USA it has an mpg of 42. See this link for the RX450 USA figures http://www.lexus.com/models/RX/detailed_specifications.html
Also, this is how the figures are calculated for the UK.......
How is the fuel consumption test conducted?
The test is outlined in Directive 93/116/EC as amended by Regulation (EC) 692/2008, and provides results that are more than representative of actual average on-road fuel consumption than previous tests. There are two parts: an urban and an extra-urban cycle. The cars tested have to be run-in and must have been driven for at least 1,800 miles (3,000 kilometres) before testing.
Urban Cycle The urban test cycle is carried out in a laboratory at an ambient temperature of 20oC to 30oC on a rolling road from a cold start, i.e. the engine has not run for several hours. The cycle consists of a series of accelerations, steady speeds, decelerating and idling. Maximum speed is 31mph (50km/h), average speed 12mph (19km/h) and the distance covered is 2.5 miles (4km).
Extra-Urban Cycle This cycle is conducted immediately following the urban cycle and consists of roughly half steady-speed driving and the remainder accelerations, decelerations, and some idling. Maximum speed is 75mph (120km/h), average speed is 39mph (63 km/h) and the distance covered is 4.3miles (7km).
Combined Fuel Consumption Figure The combined figure presented is for the urban and extra-urban cycle together. It is therefore an average of the two parts of the test, weighted by the distances covered in each part.
My apologies. I thought it was a warm engine but its not. However I think everyone will agree that at an average speed of 12mph a hybrid will get amazing fuel economy. Is this true to real life???? the whole test is 6.8 miles. on a rolling road at Uk summer time temperatures. no wind resistence, no hills. no stopping for traffic lights etc. Once you know this you realise the test is flawed. The biggest victims will be the people who buy plug in hybrid vehicles that claim up to 200mpg. but based on this test they will be in electric for most of the test!!