interesting dyno test

[yannis]

If you double-click on the icon , it maximizes a little.
http://i77.photobucket.com/albums/j68/mousatos/30032008233.jpg

Rpm's are on the left, horspower all the other columns.
Subaru liberty RS turbo, oil temperatures at 95-97 C , water temp 85-87.
Royal purple was of unknown viscosity , probably 0W-20 or 0W-30.

 

[globey]

I think I've seen that before but I'm uncertain because it is so hard to read. Still, I don't know any of the specifics of the test and I'm very suspicious of tests like this.

 

[Pablo]

I can't read that.

 

[Quest]

The variation between the horsepower produced under same RPM in a controlled dyno environment in this case is rather significant (do I see 3hp+ variation between different grades?)

One will have to cite the source of this material, and all other creditable information before this can be taken seriously, otherwise, this is nothing more than just an observation.

Q.

 

[yannis]

It was written in a lubrication book and i had it in my album for quite some time.
The reason i post it now is that i keep reading positive posts in various forums about how good mobil 0W-40 revs . Lately amsoil 10W40 became popular in Greece and i read positive comments for its indurance under pressure and some negative comments about the horsepower output.
Additionaly i have read quite a few posts here on how GC felt heavy in some engines .
Castrol R 10W60 has a HTHS of 3.7 which explains to an extent the good performance.
I am not trying to prove anything, i ve just had some obresvatios that correlate with this test.

 

[yannis]

Originally Posted By: Pablo
I can't read that.


Time for new glasses Pablo.

 

[Johnny]

yannis, have you tried the Amsoil 10W-40 oils? It's a pretty good oil.

 

[Tempest]

How does an engine make different horsepower at the same rev's regardless of what oil is in it??

 

[yannis]

Not yet , i drive an old car and use relatively cheap oils. Maybe in the near future , i plan to buy a new one soon.

 

[jpr]

It cites a different test engine, but otherwise there seem to be a lot of similarities with this 1998 test, including the "no SAE rating" on the Royal Purple - http://www.performanceoilnews.com/oils_against_oils.shtml

 

[Lazy JW]

Originally Posted By: Tempest
How does an engine make different horsepower at the same rev's regardless of what oil is in it??


Easy. Less drag enables the BMEP to go up even if the positive pressure remains the same.

 

[glennc]

Different oils can be expected to provide different efficiency (or output), on the order of 1-3% typically. 3% would be unusually large but is possible between different grades.

 

[Pablo]

Originally Posted By: yannis
Originally Posted By: Pablo
I can't read that.


Time for new glasses Pablo.

OK. I still can't read that. The numbers I can read only vary enough to account for viscosity - so it's to be expected. The RP is very low vis oil there right? Looks like it has lower HP numbers. Weird.

 

[Leo]

Interesting to see that some oils performed better at lower RPM. Eg the Amsoil 10W40 made more power than the SLX 0W-30 at 3000rpm but was vice versa at 7000rpm.

 

[BerndV]

Originally Posted By: Tempest
How does an engine make different horsepower at the same rev's regardless of what oil is in it??
The variable that can change at a given rpm in the horsepower equation is torque. Keeping it simple, T=FR where F=force and R=radius; force can increase with a reduction in friction, a decrease in fluid drag, and a reduction in pumping losses, among other things. Thus, P=(T*N)/5250 where P= power, N=rpm, if T increases then P increases.

 

[glennc]

Torque and horsepower are both variables that can change at a given rpm. In fact, if one changes, the other one has to change, because at a given rpm they are proportional to one another.

 

[BerndV]

Originally Posted By: glennc
Torque and horsepower are both variables that can change at a given rpm. In fact, if one changes, the other one has to change, because at a given rpm they are proportional to one another.
Correct. However, as I described using the equations above, the variable that is directly impacted by differing lubricants is net force (torque). Horsepower changes as a result of this increase in net force when all other variables are held constant.

 

[Barkleymut]

tests like this are near imposssible to be fully accurate unless the engine and ambient temps were identical which I really doubt

 

[digitalSniperX1]

Ok, the variance in the measurements were not listed. In the second test, the max delta between max measured HP's was 10hp or something under 4%. The test procedure didn't describe any averaging done.

So no averaging (only 3 measurements at each RPM?? and no indication the 3 were averaged and 3 are not enough) from repeated runs on a give test oil and no variance provided in the measurement makes the test more suspect than a particular brand opting out.


I'd opt out too if the test/measurement methods weren't well defined and/or faulty, which are one in the same.

So while the results of this test may indicate a better performer, they are not 100% conclusive unless they're not disclosing the complete test procedure and/or the measurement tolerance was well within the max delta in HP measured.

 

[Quest]

Originally Posted By: digitalSniperX1
Ok, the variance in the measurements were not listed. In the second test, the max delta between max measured HP's was 10hp or something under 4%. The test procedure didn't describe any averaging done.

So no averaging (only 3 measurements at each RPM?? and no indication the 3 were averaged and 3 are not enough) from repeated runs on a give test oil and no variance provided in the measurement makes the test more suspect than a particular brand opting out.


I'd opt out too if the test/measurement methods weren't well defined and/or faulty, which are one in the same.

So while the results of this test may indicate a better performer, they are not 100% conclusive unless they're not disclosing the complete test procedure and/or the measurement tolerance was well within the max delta in HP measured.


Second that!