Breaking point: How much power can your diesel handle?

Depends on if it rear wheel horsepower or crank(advertised) horsepower. Rear wheel horsepower is generally 15% lower than crank horsepower numbers due to drivetrain parasitic loss. For example, a rear wheel horsepower of 360 is about 415 at the crank just like tbe 2012 Powerstroke 400 crank hp is about 340 rear wheel horsepower. My tow tune with 390 rear wheel horsepower is about 450 hp at the crank.