2011 X5 35i "greener" than 35d?

[SkipSauls]

There is some interesting information at http://www,fueleconomy.gov for the 2011 X5 models. Using the "Compare Side-by-Side" link http://www.fueleconomy.gov/feg/sbs.htm you can add up to 4 models, so I added the 35d, 35i, 50i, and M to see what the results were. I tried to post a link to the page, but that doesn't work, nor does pasting the content into the editor.

What really caught my eye is the "Energy Impact Score" which measures the "Annual Petroleum Consumption" in barrels. Based on a 15000 mile per year average at 55% city driving, the 35i uses 17.1 barrels, the 35d 17.9 barrels, the 50i 21.4 barrels, and the M 24.5 barrels. It was surprising to see that the 35d consumes more barrels of oil than the 35i. I couldn't find any information on the site about this, but I've heard/read that more gasoline can be extracted from a barrel of oil than diesel, so perhaps that is the reason.

The "Carbon Footprint" measures "Annual Tons of C02 Emitted" and the values are 9.3 for the 35i, 9.6 for the 35d, 11.6 for the 50i, and 13.3 for the M. This must also have some factor for diesel versus gasoline because the 35d would use less total gallons of fuel per year.

I'm not a greenie, despite living in the Boulder, Colorado area where lots of such folks congregate, but it does surprise me that the diesel comes off as being less "green" than the gasoline version. It seems likely that in the "real world" the 35d will be even more efficient compared to the 35i than the EPA ratings suggest, but perhaps I'll be proven wrong by the 8 speed transmission and the "Efficient Dynamics" features.

Any early 35i owners getting any indication of MPG? The 35d owners seem to report 22-24 MPG in mixed driving, with up to 30 MPG for highway trips. In my '07 335i I've been getting 22-23 on nearly every fillup, 25 MPG or so if there are some longer trips involved. It's hard to imagine that 35i could do as well as my 1500+ lbs. less car, but again, maybe those BMW engineers have worked some magic.

[Vintage]

Originally Posted by SkipSauls

Any early 35i owners getting any indication of MPG? The 35d owners seem to report 22-24 MPG in mixed driving, with up to 30 MPG for highway trips. In my '07 335i I've been getting 22-23 on nearly every fillup, 25 MPG or so if there are some longer trips involved. It's hard to imagine that 35i could do as well as my 1500+ lbs. less car, but again, maybe those BMW engineers have worked some magic.

your 35d mpg estimates are right on - my 35d has 12000 miles on it now and the gas mileage is amazing. there is no way the 35i gets nearly as good mpg but I am sure the 8 speed transmission does help a lot