New cars with high efficiency transmissions keep the revs so low to save fuel & reduce emissions. I wonder if the engine crank & connecting rod bearings are achieving full hydrodynamic separation of these surfaces? Or are these low revving engines frequently operating with elasohydrodynamic or worse, boundary oil flow at these critical bearings?
I know the finishing of the crank, cam surfaces is far better today, but what else have the OEM engineers done to address this characteristic of low rev operation? Greater pressures from the oil pump? Asking more of the bearing makers? Or is it all up to the tribologists?
I have a 2013 Nissan Maxima SV with the VQ35DE engine & CVT transmission, in my city driving, rarely does the engine exceed 1500 rpms, in-fact it spends most of the time at 1100 rpm. Good for fuel economy, and this engine has lots of torque response from down low, but I wonder about the flip side of this low revs for longevity. CVT with a high torque V6 allows for low & steady engine speed much less up & down of a traditional automatic.
FWIW, I use Pennzoil Platinum 5W30 with either a Wix or Nissan oil filter with changes at 6 months max. I will do a UOA at my next change. And no, I have no plans to try the Ester Oil from Nissan!
Thanks again for your thoughts.
Ken
I know the finishing of the crank, cam surfaces is far better today, but what else have the OEM engineers done to address this characteristic of low rev operation? Greater pressures from the oil pump? Asking more of the bearing makers? Or is it all up to the tribologists?
I have a 2013 Nissan Maxima SV with the VQ35DE engine & CVT transmission, in my city driving, rarely does the engine exceed 1500 rpms, in-fact it spends most of the time at 1100 rpm. Good for fuel economy, and this engine has lots of torque response from down low, but I wonder about the flip side of this low revs for longevity. CVT with a high torque V6 allows for low & steady engine speed much less up & down of a traditional automatic.
FWIW, I use Pennzoil Platinum 5W30 with either a Wix or Nissan oil filter with changes at 6 months max. I will do a UOA at my next change. And no, I have no plans to try the Ester Oil from Nissan!
Thanks again for your thoughts.
Ken