Here's why:
* 560 designation: The "560" in the model name indicates a 5.6-liter gasoline engine.
* Diesel options: While Mercedes-Benz did offer diesel engines in other models during this era, the 560SEL was only available with a gasoline V8.
If you're looking for a diesel Mercedes-Benz from this period, you'd likely be looking at models like the 300D or 350D.