You can look at the mathematics of it as demonstrated above.
There are simple advantages of diesel. You get substantially longer range between fillups. The midrange torque is unparalleled by any petrol from BMW, including the M5. It has 580Nm of torque versus the V10's 520Nm. This makes the vehicle extremely flexible in any situation. You are being "green" for the environment because it emits less CO² than any other X5 model (okay, the xDrive30d in the EU emits 3 g/km less, big deal). In Virginia, diesel is usually a modest $0,08/litre more expensive, but I have seen places where it is almost on par with premium petrol.
Honestly, I don't understand why anyone gets the 3.0si model, maybe someone can explain this to me. Just my €0,02.
Last edited by AzNMpower32; 02-25-2009 at 06:35 PM.