[speeder]

To achieve the performance or (close to) the mpg #s you post, they need to run on their recommended fuel. Which is premium. They are designed and engineered to run on 91 octane fuel, period. When you say that they will "happily run" on 87 octane, what you really mean is that they have safeguards built in to their engine management system to reduce performance and prevent internal damage when run on lower octane fuel than they were designed for. You cannot quote their HP and torque numbers and then in the next breath claim that you can run them on regular fuel "happily". You know that.

The turbo gas 6 is missing 125 lbs. of torque vs. the diesel, yet you claim that it's the comparable model. The V-8 is 25 lbs. different, and peaks at a higher RPM. Torque #s are the only ones that matter on a vehicle like this, unless you're planning on racing it. Torque is what turns the drive shaft. 425 lbs. is a HUGE difference from 300 lbs., with better fuel mileage to boot. I would rather have the X5d over the V-8 one 8 ways from Sunday. What's the EPA mileage on that one? Compared to the gas 6? There is no comparison.

You know that all diesel engines have a deceptively low HP # in relation to torque, (and performance in a truck-type vehicle). I would not want to own a V-8 gas X5 if it was a gift. The diesel is on the top of my want list.