we are getting close ,,,, like a little kid at xmas , im telling you . im driving myself crazy never mind the people around me . okay ,for my 2011 36 ft winnie vista ,,, v10 ford gasser ,,,, being new...
I change my Ford 5.4 modular frequently. It has only had Motorcraft syn-blend in it from day one. Depending on how busy I get, I try to get to it every 3K to 4K. If I let it go longer, the weight of the oil filter gets significantly heavier. If you don't change your own oil, you wouldn't know that and have no basis for how much time between intervals is the best.
Oil is still cheap, keep to the 3K-4K intervals and everything will be happy, happy, happy.