OSHKOSH—Piper Aircraft has partnered with jet-fueled, diesel piston-engine maker DeltaHawk to give future buyers of PA-44 Seminoles a way to bypass the looming U.S. transition away from leaded avgas.

The world's most powerful piston engine is awesomely huge, gulping huge amounts of fuel. And because of changes in shipping, ...

The Chinese-made Weichai WP13H diesel engine, unveiled in 2024, broke a record for diesel engine efficiency with 53.09% BTE.