I had been using VR1 10w30 oil in my flat tappet engines for years. It was over $5 a quart. I was happy to find Quakerstate Defy 10W30 had high enough levels of ZDDP to protect the cams in older engine for a lot less money than the VR1. The they changed the formula for Defy. So I switched to Rotella 10W30. Now it seems they have changed the formula of that and reduced the level of ZDDP. I can't find what the new level is, Does anyone know the amount of ZDDP in Rotella 10w30 T4, T5 and T6 ? I've also read that Valvoline reduced the ZDDP in VR1 is this true does anyone know the amount of ZDDP in VR1 10w30 ? I'm having a hard time finding this information and want to used the a off the shelf oil with the most ZDDP that I can find. Thank you.