Comments and Opinions on Oil Comparison

[FrankN4]

What do you think, your opinion welcome Two 30 grade, GP III oils Oil A has a 100C cSt of 10.5 A HTHS of 3.15 SM/GF-4 add pack Oil B has a 100C cSt of 10.5 A HTHS of 3.0 SM/GF-4 add pack At an "average" of 3000 miles, based on hundreds of hours of UOA research: Oil A has a 100C cSt of 9.6 TBN of 2.57 Composite wear metals of 11 Oil B has a 100C cSt of 10.1 TBN of 2.92 Composite wear metals of 8 I had a really tough time researching 2800-3200 mile OCI for these two oils. At an "average" of 5000 miles, based on hundreds of hours of UOA research: Oil A has a 100C cSt of 8.8 TBN of 1.98 Composite wear metals of 16 Oil B has a 100C cSt of 9.78 TBN of 2.24 Composite wear metals of 11 These are real world oils, discussed/cussed every day on BITOG, and extremely popular. Both are the exact same price. I cannot give the brand names now, but would love your comments. Which would you prefer?

 

[d00df00d]

I don't think the composite wear metals differences are significant. Are you sure the viscosity and TBN differences are statistically significant?

 

[CharlieJ]

The one with the higher HT/HS. I think I may know what oil A is.

 

[jmac]

Are those in same engines? If not, can't even pick the one that sheared less unless engine families are taken into account. Toss a coin, be happy with either one.

 

[ottotheclown]

You know if you could give us the brand names something could be drawn to a conclusion right here on BITOG< what a thought....

 

[jpr]

Originally Posted By: jmac

Are those in same engines? If not, can't even pick the one that sheared less unless engine families are taken into account.

Ditto - UOA's tend to vary greatly depending upon the particular engines in particular cars. If you normalize the data for a particular engine type or manufacturer you can spot some general trends, but you still have to be careful about letting a few outliers skew the averages. If along with the average values if you could include the range of values, the median value, and if you've got enough data, the standard deviation, then there would be better basis upon which to make judgments about both the performance of the oils and the significance of any apparent difference between them.

 

[jmb106]

Based on the information given I would take the higher HT/HS. I am sure i know what oil A is, I won't say now for the sake of discussion. Not sure what oil B is. Joe

 

[ryland]

If you change at 3k use either and dont worry!

 

[ottotheclown]

I know what oil these are but I swear I will never tell anyone ever... Mystery is so interesting on a motor oil web site I think it may be a full moon soon.

 

[2KBMW]

Oil B would be my choice for my cars other than my BMW.

 

[bullwinkle]

Let's see-oil A rhymes with "Gobil 1" & oil B rhymes with "Spamsoil"-how close am I?? Oil B does look a little better, though.

 

[fdcg27]

These oils look really close. Oil "B" appears to be somewhat better in performance, but the differences are not very great. Based upon what you have posted, Oil "B" has better TBN retention and less shearing over 5K miles of use. With a large enough sample group, the differences in wear metals might have some significance. How large were the samples in your meta analisys?

 

[FrankN4]

Originally Posted By: fdcg27

These oils look really close. Oil "B" appears to be somewhat better in performance, but the differences are not very great. Based upon what you have posted, Oil "B" has better TBN retention and less shearing over 5K miles of use. With a large enough sample group, the differences in wear metals might have some significance. How large were the samples in your meta analisys?

676 UOA's of oil A 408 UOA's of oil B Combined mileage of 4,952,800 miles. 248 same engine model and type but not the exact engine switching between oils.

 

[fsskier]

Now, if we ran the engines till they wore out then we would have some data. UOA's? Of course we have the conflicting information given to us that: 1. Only certain wear particle sizes measure accurately. 2. Antiwear additives that form chemical alloys can greatly reduce bore wear but can result in higher PPM iron numbers so... They are both GF4, so they pass the wear tests.... I would buy the one that is cheapest!

 

[PT1]

I'll take oil B

 

[jpr]

Originally Posted By: FrankN4

676 UOA's of oil A 408 UOA's of oil B Combined mileage of 4,952,800 miles. 248 same engine model and type but not the exact engine switching between oils.

While you've got some reasonable large samples there, I'll wager that the performance difference between the two is statistically insignificant, i.e. the variations within A and B are a few orders of magnitude greater than the differences between the averages of A and B.

 

[CharBaby]

AN--TIC-I-PA--TIOOOON!!!

 

[Jaymus]

I'd take oil B, also. Better TBN retention. Also holds viscosity better. This is still a meaningless 'comparison', imo. Now, tell me what oils these are.

 

[Gary Allan]

My comment is that if these are comparably priced synthetics ..then way too many people are doing 3k OCI's to even assemble this much data. Now if you want to base it on a time component, that might alter the field a bit.

 

[addyguy]

Oil B, for the reasons Jaymus outlined - it held 100C visc. better, and had a higer finishing TBN overall, even though it had slightly lower HT/HS value.