It will be interesting if we can use the G-5 next generation oil in our Gen3/4s.....Mobile oil 0-40 is always hard to find....Automakers switch to new engine oil for more efficiency, better protection
Motul is what John Archer recommends and what I use...
Maybe Tom will chime in here on this. I find the Mobil1 0w40 very easy to find at parts stores when I need it.