All oils pass a seal compatibility test as part of their SAE certification.
There's not really any chemical difference between most synth and dino oils.
Originally Posted By: d00df00d
Quote:
I don't need "accuracy" to compare two oils.
This should have been the end of the discussion. It's futile to argue logic with someone whose only coherent point is that he (or she) doesn't actually care about the truth.
Can we move on, please?
lol, you...
My VW is VERY sensitive to octane. I usually BYO to 90-91 but things liven up a LOT on 93. 87 is out of the question.
With a $.40c difference between 87 and 93, it's a no brainer.
I'd need +10% to break even, or 2mpg. I think I have that.
93 to 89 would be a more appropriate comparo, at...
Originally Posted By: BritGerCarLuvr
Here we are, and I've made a lot of changes & I wish to thank many members of this board for their great advice. I do, however how one more issue for which I need some clarification.
I will keep my question simple.
Q) If your car called for either oil...
You might like Rotella Synth 5w-40 or Mobil 1 High Miles, 10w-30 or 10w-40.
Since you're open to suggestions, try some 2-cycle oil in the fuel at 500:1 (3oz 10g) Add some extra the first time.
Originally Posted By: GMorg
Audi Junkie, if the issue is A3 vs A5 cold viscosity, then why doesn't the graph above that includes GC (A3) and Edge 10W30 (A5) demonstrate the opposite of your position. Doesn't it show the A3 oil as thinner than that the A5 oil via the calculator?
Ding.
Someone...
Just a reminder, the subject is A5 vs A3, not visc calcs. Maybe you guys should let Shell know their online calc is so fatally flawed.
Again, it's not a matter of accuracy, were not launching satellites, it's a tool to make a rough comparison between 2 oils. I have yet to hear a better method...
Originally Posted By: JHZR2
Ummm, yeah you do. Plug in a 1 cst difference at 100c and see what it does to your curves. Try a similar error at 40c.
Need to work on your math.
So changing the data to skew the results? lol, that sure is "working on the math".
Originally Posted By: Falcon_LS...
Originally Posted By: GMorg
To be classified as 5W40, the M1 that is graphed above has be be less than 6600 cP at -30C. cP and cSt are measured different ways, but are essentially equal units. So M1 5W40 must have a viscosity of less than 6600 cP at -30C and the graph shows it at nearly 18,000...
The graphs are based on logical scientific principles, well-known in the industry. What's speculative is the idea there's a variance from the extrapolated values....YOUR speculation. You have no idea WHICH oil is at a greater or lesser value, do you? For all you know, the oils could diverge even...