Tyee II
Registered User
Have always ran the Delo or Rotella 15-40 in my IDIs. Seems to be some movement to the 5-40 synthetic recommended for the newer engines. My understanding that this can help with an injector problem called stiction on cold start up. This being due to the engine oil being used as a hydraulic medium in the firing of the injectors and the 5-40 synthetic has better hydraulic properties particularly when cold ? I realize the IDIs do not have this function. Is there any benefit or negative reason to use or not use synthetic 5-40 in an IDI ? Has anyone made the switch and if so what benefits have come with using the synthetic ?