My opinion?

The Diesel option is not worth it purely from the aspect of fuel economy/cost, due to the higher cost of diesel, the inconvenience of finding diesel, and the added complexity of the adblue injection system, which is likely to be expensive to repair if you keep the vehicle a long time.

OTOH, the diesel gives better performance with its high torque at lower RPM, and is an additional incentive for the diesel over the NA six.

At $4k I am not interested, at $2K I would definitely go for the diesel.

Personally, I am going to wait for the 2010 model and hope BMW puts the twin turbo gasoline six into the X5.

I had my 35d since December and I don't regret it.
I think it is worth it even thought I could have saved $10K if got the 3.0i gasoline version.
The torque and speed is incredible, a lot of passing power.
It is almost as fast as the V8 (less HP but more torque power for the 35d).

BMW advertise their diesel to be 30% more efficient, so that means diesel fuel would have to be 30% more expensive than premium gasoline and you are still even on cost. Where I am diesel is same as premium or a few cents more per liter. So I send less on fuel for the my 35d than my 4-cylinder premium gasoline sedan.

Sure the adblue is an extra cost but minor cost to having clean exhaust and not smelling that toxic CO2. You can say you are being environmental to all your friends (and to GOD :-).
What I smell now is water vapor (smells like a hot bath) from the exhaust.

No issues at all in the cold weather (-37* C)
The noise level of BMW diesel engine is about the same a gasoline engines but still a diesel distinctive diesel sounding engine.

Negative things:

One thing I don't like is, when you are run out of adblue and you shut the engine off. You can't start it again, the computer disables the vehicle. That is stupid! But it will warn you that you have 2000miles of adblue left.

Oh' another thing is no spare tire! And you have to have runflat tires in order to get BMW roadside assistance on tire related issue.

Also at Esso, you get 1 point for every dollar you send on diesel fuel where as you would get 3point for every dollar you send on premium gasoline.
That is a big difference in collecting point for car washes (500points for luxury touchless wash).

Again the adblue is an extra cost and inconvenience, but it is minor...

So, you can decide for yourself

Not withstanding the prices and the equipment of the various models offered in various markets, comparing the diesel (especially the twin-turbo) to the 3.0-litre petrol is barking up the wrong tree. In terms of performance, the twin-turbo diesel is stronger than the V8 for everyday road use, the V8 only just nudging it out at silly speeds. As for the 3.0-litre petrol, it isn't even in the hunt.

IRS Form 8910 (when available) will provide the details. It's not available in final or draft form at the moment.

http://www.irs.gov/pub/irs-pdf/f8910.pdf

The post above is correct in that there will be a phase down of credit as your adjusted gross income goes up.. If I remember correctly from 2007's form, > $175K'ish, no credit at all.

Interesting to note that For Toyota and Lexus vehicles, no credit is allowed for 2008.

Other related links:

http://www.irs.gov/publications/p17/...blink100035228
http://www.irs.gov/newsroom/article/...7557%2C00.html
(no 09' updates available)

The urea will be available at most truck stops in the future. All 2010 model diesel vehicles will be required to run urea. The fluid is the same for all vehicles is what I've been told...

Craig

Diesel is fine, had many Bimer oil burners, but no diesel can match the feel of true Bimer V8 petrol at any speeds or bends. After 3.5k rpm oiler gets flat. Hard every day driving + high mileage means high maintenance costs for oilburners. Diesel high quality is a must. 35sd too many moving parts - two turbos, two intercoolers, lots of pipes several fuel filters, so lots of stuff to go wrong.