I decided to do a quick test of the various oil sitting in my garage to see how it looked when its cold. I kicked three oils out into the driveway for the afternoon, temp about -20F.
Mobile One 5-30w synthetic (used in "her" subaru), still very fluid at -20 would pour easily.
Delo 10-30w petro based. fairly fluid would pour about like honey at room temp.
Rotella 15-40w, not very fluid. poured quite slowly, about like honey in the fridge.
I have this rotella in my truck right now and got the lighter delo because it takes soooo long for the oil pressure to register, even with the oil pan heater. I have used Delo before in the summer and found it got dirty faster than rotella and didn't feel as smooth. But I was surprised at how much more fluid it was vs. the 15-40, so I will swap it out and see if it starts and brings the pressure up faster.
Mobile One 5-30w synthetic (used in "her" subaru), still very fluid at -20 would pour easily.
Delo 10-30w petro based. fairly fluid would pour about like honey at room temp.
Rotella 15-40w, not very fluid. poured quite slowly, about like honey in the fridge.
I have this rotella in my truck right now and got the lighter delo because it takes soooo long for the oil pressure to register, even with the oil pan heater. I have used Delo before in the summer and found it got dirty faster than rotella and didn't feel as smooth. But I was surprised at how much more fluid it was vs. the 15-40, so I will swap it out and see if it starts and brings the pressure up faster.