Originally posted by javaContour:
In the summer time, I would be more comfortable with a 10W-30, especially if it is a traditional (non-synthetic oil). Why? Because there are fewer viscosity index improvers in the 10W-30 oil. There is less spread between the two weights. For a synthetic, this is not as much of an issue, but still an issue to some extent.
Mobil 1 5W30 uses NO viscosity index improvers...
One of the biggest reasons I use it over AMSOil Synth.
I agree that with a dino oil in the summer; 10W30 & 5W30 would be hard to tell apart at cold temps (70, 80 degrees) and the fact that 10W30 has less V.I's would be a nice plus.
I don't run dino though for numerous reasons...
