Well my friend has not gotten me the exact specs on volitality for Castrol and some of the other oils but he did send me this general Info that I will put up now.

Noack Volatility

Noack Volatility is a measurement of the amount of oil which is lost during engine operation because of burn-off.

There are several concerns associated with oil volatility. First, engine oil is lost and must be replaced. Additionally, the viscosity of the remaining oil increases. Moreover, oil loss could change the effectiveness of the oil as a lubricant and start to gel into sludge . The chemical properties and additive package ratio of the oil may also change as the volatile components are burned off and additives can become a contaminant increasing the acids and creating more strain on the remaining oil. Finally, there is also evidence that the volatilized oil may damage the exhaust catalyst as it passes through.

The volatility of an engine oil is measured using ASTM test method D5800 (NOACK Volatility % Evaporation Loss (ASTM D-5800)). A known weight of oil is heated to 250°C in a special chamber and held at that temperature for one hour. Air is introduced into the chamber and maintained at a constant flow rate under slight vacuum. After one hour, the amount of oil remaining in the chamber is weighed again. The percentage of oil lost is determined by comparing the remaining weight of oil with the original weight of oil.

Specifications set by ILSAC determine that the amount of engine oil lost through volatilization at 250°C for one hour should not exceed 22%. Of course in this case the lower this number the better the oil will hold up and no additional oil will be needed between oil changes.

Another important but yet not normally available test on tech data sheets for determining oils capability of oil resisting oil gelling/sludge is


My friends site that gave me the info http://www.synthetic-solutions.com



-----------------------------------------------------------------------------------------------



I know BMW has come out with a recommendation of 15,000 miles or once a year in regards to oil change intervals.

(A Friend of my wifes at work has got a new BMW "2001" with these recs in the manual, I am assuming that the relationship between the Mini Cooper and the BMW would dictate that the recs are similar, Her friend also told me that they recommend Castrol which would lead me to believe that Castrol has secured some type of Contract with BMW)

The only problem is that they are factory filled with Castrol Syntec. A Group III Hydro cracked Oil. They are having oil consumption issues due to Volatility. If they used a "true" synthetic (traditional definition) then they would probably have much better results. The "Noack Volatility Test" has been utilized by European regulatory agencies for years as a means to benchmark the quality of an engine oil. Amsoil is the only North American manufacturer to utilize the same criteria to establish a benchmark.

BMW needs to be careful about the quality of the product they are using as a Factory Fill. Apparently Mercedes-Benz is having some difficulties as it relates to extended drain intervals as well. Their is a class action suit that was recently settled by MB for customers who were never told that they needed to use synthetic oil for the MB extended drain interval recommendation.

http://www.classactionamerica.com/ca...e.asp?cid=1834

Also see this link as it relates to Volatility, (Keep in mind that test results change from year to year)

http://technilube.hypermart.net/sect...est/noack.html



To me, these are all very interesting issues to me as you can imagine. We (Amsoil) have been promoting extended drain intervals since 1972. I think if you do some searches for Noack Volatility you will find some valuable information to offer on the forum you are participating in.

 

Bump

 

I agree. I don't think there is a problem using Castrol Syntec, if you change it every 2500-3000 or less, depending on driving style, etc. I wonder why, on my BMW motorcycle they recommend regular oil for the first 20,000 then switching to synthetic. Any thoughts on that? It is the reason I am going to let Mini change my oil with Castrol but once I get some miles on the car, then I'll switch to full synthetc. I've heard different theories about the advantage of regular oil for break in but they are not real clear. Thanks.

Florida Mini Owners

 

Generally for modern engines the cylinder walls are honed to such exacting specifications that there is no real break in period for the rings. This can be seen by the fact that all new vettes and the late great F-Bodies came with Mobil 1, a true synthetic, in the crankcase from the factory.

According to GM this is perfectly find because of the very exact tollerances they build the motor with. Modern motors are also started at the factory and run for a short amount of time to do the main break in. I assume that with the vettes and F-Bodies that this is done before the mobil 1 is put in.


Generally at my shop i recomend somone wait one or two oil changes, 3000-6000 miles, before they switch to synthetic in a gas motor. I would recomend a little longer on a diesel, around 10,000 miles, since they generally take much longer to break in then a gas motor.


For the motorcycles i am not sure about. Probably something to with the much higher RPM's and higher HP/litre that the motorcycle motors put out.