Not any more. The US now requires low sulfer fuel. The new engines are designed for the new fuel, but the older engines require an additive to restore the lubricity previously provided by the sulfer.
I have an '87 Ford 4x4 pickup/camper with the 6.9 Navistar diesel. It will tow my jeep at 65 mph all day long and still get 16-17 mpg (not bad for an 8,000 lb tow rig and 4,300 load), and diesel fuel costs less than regular octane gasoline. When it wears out, in another 250,000 miles, I'll get another diesel.
Robert Bills KG6LMV Orange County CA