FWIW, Rotella no longer packs the zinc additives they used to into their mixes. They stopped doing that to comply with they new diesel emmission bullshit that was passed a few years back. If you’re still looking for the zinc and molybdenum, you’ve really got to add it(Lucas)
Yup, in the winter I drop to the 5w so the motor isn’t pushing maple syrup up to the lifters. I’m also afraid that pushing the 15w cold through the oil cooler will split it(it’s not thermostatic, runs open constant to keep oil temps below ~110c on these motors)