The owner's manual for a Kia calls for 75W-90 gear oil in the rear differential and the driveline clutch pack/center diff. It doesn't specify synthetic. I'm most interested in low running resistance and fuel savings; the rig isn't run heavily loaded.
Are there any conventional 75W-90 gear oils, or are all synthetic? (I think so, but I'm not sure.)
Is there any real difference between the top brand syn gear oils? I know that Amsoil, Royal Purple, Mobil 1, Red Line and others all have their adherents, but aren't all excellent?
Are there any conventional 75W-90 gear oils, or are all synthetic? (I think so, but I'm not sure.)
Is there any real difference between the top brand syn gear oils? I know that Amsoil, Royal Purple, Mobil 1, Red Line and others all have their adherents, but aren't all excellent?