My diesel

I have owned diesel cars since I purchased my first diesel VW Rabbit new in 1978.
Although my PIP has almost 50% of its driving as an EV, I still rely on my current diesels for trips to visit the kids in Southern Cal because a turbo diesel has no power loss from altitude going over the Grapevine and used for long distance driving it gets very good MPG provided I drive at Autobahn speeds.
At 4200 lbs this is German luxury sedan with all of the bells and whistles you could want but it only gets "fair" MPG driven around at normal USA speeds.
Real world MPG on city streets is around 23 MPG and freeway driving in an urban environment yields about 32 MPG. The engine turns less than 1800 RPM at 70 MPH and is sitting at start of the fat part of its torque curve (369 ft/lbs) at that speed so acceleration is very dramatic with only a gentle nudge of the throttle.
However, a speeds above normal urban traffic speeds the diesel is in class by itself.




The first image shows the average MPG after driving with the cruise control set at 100 MPH for a distance of 50 miles, while the second image shows the average MPH after driving with the cruise set at 80 MPH for a distance of 50 miles.
The car is a Mercedes E 320 CDI which was part of a group of 50 hand built engineering prototypes built in 2003 as proposed 2005 models to test how the cars smog system would survive on the dirty high sulfur USA style low grade diesel fuel which was the only type of diesel sold in the USA at that time. The test went well but before the production of the 2005 models was set to start the smog requirements in several states tightened and to meet the new requirements, the upgraded smog gear required European standard ultra low sulfur diesel which was blocked from sale in the USA at the request of the American Trucking Association because ULSD diesel would have raised the cost of diesel fuel by an extra .05 / gallon. A modified version of this car was finally offered for sale in non CARB states staring in 2007.
The remaining prototypes were returned to Germany to be scrapped but a few were saved.