Originally Posted By: sdude2k2000
Originally Posted By: CATERHAM
You can check out my opinion in detail on RL's 5W-20 grade in the recent VOA posting.
But basically it is a 30wt oil in all but name and it's hard to imagine any 20wt application for which this old formulation is suitable. RL's own 0W-30 is a more modern and clearly superior formulation that is actually lighter at all start-up temps as high as 90F and is equally shear resistant.
All of what you said is fine, however you didn't directly address my statement. Your classification of the 5w20 variant is irrelevant, please explain how you decipher quality oils from the viscosity index.
Redline 0w20 = 166
Redline 5w20 = 145
Redline 0w30 = 183
Redline 5w30 = 162
Redline 10w30 = 142
Pennzoil Ultra 5w20 = 158
Pennzoil Ultra 5w30 = 169
Pennzoil Ultra 10w30 = 156
Are you to say all these oils minus the 0w30 are
not good oils due to their "subpar" viscosity indexes? By your standards, the Ultra line is superior to every equivalent grade Redline oil.
PS - No I'm not a Redline pimp, just using an oil everyone can agree is very highly regarded for comparison & to make a point.
Any multi-grade synthetic with a VI less than 160 is clearly "subpar" as you put it, and better choices are available.
BTW, the two 10W-30 grades you've mentioned are redundant and are not worth buying as their 5W-30 counterparts are the same price and can outperform in every application. It's a "marketing grade" targeted at consumers that don't know any better.