I'd run the Amsoil 0w-30 in both these engines, provided they are mechanically sound. I have been using this oil year round in Huntsville, Alabama and Palmdale, California for the last seven years and have seen no problems with oil consumption. I have no experience with the Mobil 1, 0w-30 but the Series 2000 stuff is simply an excellent - and very expensive - product. If you run it in an engine where the idle speed isn't electronically controlled you will have to turn down the idle speed significantly after 5-10 hours of use. Try running a quart of this in a riding mower and you'll see what I mean.
TooSlick
TooSlick