Out of Mobil 1 0w30, Mobil 1 Truck and SUV 5w30, Mobil 1 5w20, Pennzoil Platinum 5w30, and Pennzoil Platinum 5w20 which is the thickest and which is the thinnest?
You have to specify a temperature to compare viscosities. The rank order might be different depending on what temperature you're looking at.
For example, if you compare them all when they're stone cold, Mobil 1 0w30 might be thinnest. If you compare them all when they're hot, one of the 5w-20 oils might be thinnest.
A 0w-xx would be better for winter than a 5w-xx because it will have better cold flow properties.
Between a 5w-20 and a 0w-30....does you owner's manual specify 20 or 30 for the second number? I would pick an oil with the recommended second number and a 0 for the first number.
Originally Posted By: dsmith41
A 0w-xx would be better for winter than a 5w-xx because it will have better cold flow properties.
Depends on how cold you're talking. A 0w30 will only be thinner than a 5w-20 in the absolute coldest temperatures. Above that, it'll be about the same or thicker.
Originally Posted By: dsmith41
Between a 5w-20 and a 0w-30....does you owner's manual specify 20 or 30 for the second number? I would pick an oil with the recommended second number and a 0 for the first number.
Originally Posted By: ARCOgraphite
I dont think Castrol 0w30 is really a 0w if you extrapolate the curve from 100cst > 40cst, its 40cst is much higher than many 5w conventionals.
(Assuming you meant degrees C instead of cst)
The winter rating is measured well below 40 degrees C.