The 224g/km D5 185bhp engine was introduced in build week 21 2008 and covered late MY2008 (except R Design and Exec models) and all MY2009 (except early R Design and Exec models) cars, I was told that week 21 was the last week in May 2008.
I recd this info from Volvo UK when I was buying my MY2009 XC90 in March this year.
Hope it helps
