Who has their oil analyzed?

[Steve 00RT/10]

I think this is all good info. Doing a quick comparison from Ron's charts back to my numbers shows my Amsoil, with 6K miles, to be higher in some of the critical additives Tom mentioned than the ****** samples..including the Mobil Delvac. I'm not trying to make this into an ad, but it is reassuring to me to know that it stacks up pretty well so far. I would encourage anyone with a different oil--synthetic or otherwise, to throw their numbers out here. If there's something better to use, Im all for it.

Steve

 

[Tom F&L GoR]

A note: The additive metals (i.e. calcium, molybdenum, boron, etc.) do not disappear with use, they change their chemical form. So the level of detected calcium stays at 2000 ppm, for instance, during the entire oil drain interval. Of course, the wear metals (iron, lead, etc.) will start at zero and go up from there.

Another note: Don't assume that Mobil (or any brand) 5W-20, 10W-30 and 15W-50 will all have the same additive package. The lower viscosity grades may have more additives due to OEM requirements for fuel economy or thermal stability that don't apply to other grades. The higher viscosity grades may have extra performance because they were formulated to meet European requirements. The middle grades are often the skinniest package because the performance requirements are the least.

 

[Steve-Indy]

Thanks (AGAIN), Tom. One of the things that worries ME is that MOST of us end-users tend to fix on a microscopic point or two, then proceed to plot a whole oil strategy based of scattered facts, myths, anecdotal remarks, personal observations/habits and hearsay...and miss the overview that YOU real professionals have worked so hard to to achieve. I SURE intend to analyze ANY oil going into our Vipers...as well as that coming out...but I realize that with 3 Generations represented and the random differences in utilization patterns of each Viper certainly will prevent ME from drawing LARGE conclusions from only the analysis data....BUT, it's FUN to indulge !!!

 

[ninjaviper]

Clarification please.--In an earlier post, Tom noted that oil viscosity for xxW30 should be between 9.3-12.5. However, Ron's recent post on ****** 10w30 notes oil viscosity of 57.8. I'm confused. Please discuss.

Also, if oil viscosity is actually below 9.3, does this mean that you are using a different weight oil,i.e. 10W20?

 

[Ron]

ninjaviper - Viscosity can be measured at various temperatures, typically 100 degrees F and 210 degrees F. My numbers are measured at 210 degrees F.

In addition, there are cST and SUS viscosities along with a viscosity index. Tom will have to help us with these definitions as I have no clue......

 

[Tom F&L GoR]

Ninja and Ron-
Current SAE practice is that oils are measured at 40C and 100C, although it has been measured at 100F, 210F, and other temps in the past. The range I was referring to is at 100C; i.e. 9.3 to 12.5 cSt at 100C.

Ron, your numbers look like cSt at 40C;

cSt = centiStokes, named after Mr. Stoke. SUS = Saybolt Universal Seconds, named after Mr. Saybolt. Most of these viscosity measurements are based on how long it takes for the fluid to pass through a certain size capillary tube.

The Viscosity Index is the "slope" of the viscosity change from 40C To 100C. A normal mineral base oil has a VI of just about 100 (for instance, a single grade SAE 30), a synthetic base oil has a VI of about 120. A multigrade oil has an additional additive to increase the VI in some viscosity grades to about 180 (such as a 0W-30 or 5W-40).

 

[Tom F&L GoR]

Ninja,
If the oil started out over 9.3 cSt, and analysis shows it's under, then the oil is either diluted with fuel or the viscosity improving additive has sheared enough to allow the oil to thin.

This site (click on Physical Requirements of Engine Oils) has a table of what the ranges are.

 

[ninjaviper]

Tom: One additional question-- If oil analysis demonstrates oil viscosity of 9.1, does this mean that the oil cannot be 10w30 or is this within the margin of error for testing. I had my oil tested and I assumed it was 10w30; however the analysis demonstrated viscosity of 9.1. Is this of any significance as far as engine performance, reliability, or safety is concerned. When the oil was tested, the car had only been driven 20 miles.