Amsoil test results...

[TooSlick]

Pablo,

How do you think Mobil 1 was being sold at Walmart for < $4.00/qt, in five quart jugs not that long ago? They certainly weren't taking a loss on that and Walmart had to make a profit as well....

I think Bruces numbers are about right, but I'd also include transportation costs to the seller. I believe that British Petroleum makes PAO's in house, so their main basestock costs may be quite low.

 

[bruce381]

do I have to show you a base oil invoice??
bruce

 

[Pablo]

It's not that I don't believe your numbers - I just thought GC was not Mobil 1 type low cost PAO. I don't feel like digging out my email from Terry.

I still think the cost is more the $2.70/qt at the store, but you're the expert.

 

[KW]

quote:

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Originally posted by Ken2:
For example, the 4-ball wear test is not relevant to motor oil performance inside an engine. It is an imprecise test of gear oil and grease.

Ken

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I think the 4 ball wear test is a great tool to replicate what happens with valve train wear.

KW

 

[Louie's gone fishing]

I'd hate to see the valve train that looked like a 4-ball wear tester. If it's like the one I've seen for grease testing, I think a valve train's wear surfaces fit each other a bit better.

The best oil test device I've seen is a funnel with a full mark and a legend that tells you what viscosity an oil is by the time it takes to drain and a color a seperate color chart, all to be used when one is picking an oil for the next oil change. I think it's a bit out of date, now, but interesting. Somethings in life are a bit easyer.

 

[TooSlick]

The four ball is a typical analog wear test....

The reason for using 1/2" ball bearings is to reduce the contact area between the load ball and the three wear balls. In this way you can achieve pressures in the tens of thousands of psi with a fairly low force on the load ball, in this case 40 kg, or 88 lbf. If you calculate the pressure on each of the wear balls when the scar has progressed to say 0.1 mm, you'll see it's extremely high.

The other reason for using spherical contacts is that it makes the test geometry fairly insensitive to the viscosity of the fluid. So you are essentially testing how well the AW additive chemistry works to minimize wear under boundary lubrication conditions.