Hi all. I was wondering the same, if lower SAPS oils keep engine more clean, even engine has no DPF or low/mid SAPS is not required?
I have an Ford Mondeo 1.8 TDCI year 2008 (european model). Car has now an issue with VGT turbo vanes sticking and therefore a turbo change is scheduled in few weeks.
Car manufacturer OCI is 20000 km. I've changed oils and filter at 15000 km OCI, and I've always used oil according to spec (WSS-M2C-913-D) and those are usually full-SAPS (ash about 1,3%).
Mobil however produces Super 3000 FE 5W-30 with mid-SAPS (ash 0,8%) and it has Ford approval too. I'll try that hoping to increase new VGT turbo lifespan. So it may not form so much soot or carbon onto vanes and cause them to stick so soon? Although the current turbo has 260000 km's and 12 years of service, but I've expected for more of course.
So, how you think, does lower SAPS content engine oil help to extend i.e. variable geometry turbocharger life or improve general engine cleanliness?