jus2shy wrote:
For the 3.0 Ecodiesel with 159 vehicles, 2,873 fuel ups and 1,288,000 miles they note a fleet average of 22.81 mpg. So about a 5 mpg difference between the two. Depending upon perspective, and increase of 28% more mpg over the Ford, or a decrease of 22% from the RAM. Take it for what it's worth.
You also have to account for the increased costs of fuel for Diesel. It's not the same everywhere so you should do your own calculations for your area.
We can use this as an example: http://www.gasbuddy.com/Station/28991
Regular : $2.25
Diesel: $2.59
Diesel is about 15% more expensive than gas. So the MPG increase is not that great and a wash wen you add in the increased cost to acquire and increased maintenance costs of the Diesel.