I run conventional SuperTech 10W30 except for the winter months when I switch to 5W30. On the otherhand, my Elantra calls for 10W30 as a primary weight oil. As for Mobil 1, my feeling would be it's properties would be such that either weight would do well at any time.
I had run 5W30 exclusively in a Cavalier for the first 75,000 miles and switched to 10W30 because the engine was beginning to (slightly) use oil-- one quart in about 3000 miles. I didn't notice any better oil consumption by going to a heavier oil.
Here is a comparison of various weight SuperTech specs. for their SJ oil. I've bugged the Pennzoil people enough over the years. You might want to contact them through their web page and see if they have updated specs. also if the specs. will change when they close down the Shreveport blending plant. My suspicion is that production will shift to one of the Equilon plants and the oil will look a lot more like Shell-- or the old Havoline, but that's just a guess.
Super Tech SAE Grade(SJ) 5W30 10W30 10W40 20W50
API Gravity 30.7 30.3 31.3 27.9
Viscosity cSt 40C 67.0 73.2 104.0 170.5
Viscosity cSt 100C 10.7 11.0 15.2 19.4
Visc@100F SUS 342.0 376.0 532.0 887.0
Visc@210F SUS 62.8 63.9 80.3 98.3
Visc. Index 155.0 140.0 152.0 121.0
Flash Point c (F) 207(405) 210(410) 221(430) 227(441)
Fire Point C(F) 221(430) 227(441) 232(450) 235(455)
Pour Point C(F) "-37(-35) "-34(-29) "-34(-30) "29(-20)
Viscosity cP, Max 3500@
"-cp Max, 4500 "-25(-13) "-20(4) "-20(-4) "-10(14)
Low Temp Pumping C(F) "-30(-22) "-25(-13) "-25(-13) "-15(-5)
Viscosity cP Max 30,000.0 30,000.0 30,000.0 30,000.0
I had run 5W30 exclusively in a Cavalier for the first 75,000 miles and switched to 10W30 because the engine was beginning to (slightly) use oil-- one quart in about 3000 miles. I didn't notice any better oil consumption by going to a heavier oil.
Here is a comparison of various weight SuperTech specs. for their SJ oil. I've bugged the Pennzoil people enough over the years. You might want to contact them through their web page and see if they have updated specs. also if the specs. will change when they close down the Shreveport blending plant. My suspicion is that production will shift to one of the Equilon plants and the oil will look a lot more like Shell-- or the old Havoline, but that's just a guess.
Super Tech SAE Grade(SJ) 5W30 10W30 10W40 20W50
API Gravity 30.7 30.3 31.3 27.9
Viscosity cSt 40C 67.0 73.2 104.0 170.5
Viscosity cSt 100C 10.7 11.0 15.2 19.4
Visc@100F SUS 342.0 376.0 532.0 887.0
Visc@210F SUS 62.8 63.9 80.3 98.3
Visc. Index 155.0 140.0 152.0 121.0
Flash Point c (F) 207(405) 210(410) 221(430) 227(441)
Fire Point C(F) 221(430) 227(441) 232(450) 235(455)
Pour Point C(F) "-37(-35) "-34(-29) "-34(-30) "29(-20)
Viscosity cP, Max 3500@
"-cp Max, 4500 "-25(-13) "-20(4) "-20(-4) "-10(14)
Low Temp Pumping C(F) "-30(-22) "-25(-13) "-25(-13) "-15(-5)
Viscosity cP Max 30,000.0 30,000.0 30,000.0 30,000.0