Leaching of RTV silicone from the oil pan gasket into the oil causes the foaming. Foamy oil interferes with fuel injection, which reduces engine power. The ASTM D 892 Foam Test, Sequences 2 and 4, are used to evaluate diesel oils on their foaming characteristics relevant to this engine.
Recent testing performed by an independent lab shows the results below.
The test also shows AME and HDD dissipate foam more quickly than Rotella T, a popular diesel oil often recommended by Ford. Faster foam dissipation means reduced foam related driveability problems. Let your customers know that silicone leaching diminishes with increased engine mileage, and in the meantime the solution to foam-induced driveability problems, regardless of oil brand in use, is an oil change.