I work on an offshore oil platform and when we instaled new bulk air compressors and mud transfer pumps we were having problems traced back to oil. Had royal purple give demonstration at one of the mechanical schools and decided to switch to their oil. Belive it is 20/50. Have not had problems since going on 5 years. This mud can weigh as much as 18 lbs per gallon. Bear in mind this eguipment run pretty much 24/7 and oilfield hands are notorious for being "rough" on equipment.

Do any of you do oil analysis to determine how the oil is actually performing or for one oil versus another oil comparison? If yes would you post results?

We do oil analysis on my dads 288 Sunsation. At 100 hours the oil was still perfect, no wear metals and the additive package was still strong. He does however use the AMSOIL Marine Bypass filtration system, which does help. To those of you who have started using Royal Purple, be careful with their products, its not as good as it used to be. It is a highly refined petroleum product and does not have the same strength as it once used to. Here is a link to an independent study of gear lubes, but it gives you the idea of how Royal Purples products stand up to others. Some categories they are good, but some, they absolutely fail the tests. http://www.amsoil.com/products/gearl...hitePaper.aspx

You can download this brochure.

I have one season on each of : Merc 25W40, Valvolene 20W50 V-Twin and Amsoil 20W50 Series 2000 racing oil. Unfortunately each winter I made significant modifications to the engine so the comparisons are undermined. The Merc was a refill when the original oil was changed after breakin and had the best marks. The Valvolene 20W50 V-Twin was used after new heads (ported) and new cam/valve train intake manifold ported/polished and ECU reprogram with breakin of those. Additive Package still solid but more wear products and a little fuel which were likely from the break in of new components and reassembly of engine. The Amsoil 20W50 Series 2000 racing oil was used after the heads were additionally ported, new cam, new exhaust, timing advanced slightly and ECU reprogram. The oil had very high fuel content so viscosity was down and wear products similar to previous oil. Engine hours were 90/80/50 respectively. This time engine completely torn down and lots of new parts going in. After breakin using Amsoil 20W50 Series 2000 racing oil again.

Have you tried other oils in the same motor and run analysis that you can compare results for same operational conditions?

Rage,
No, I haven't done any comparisons on Marine applications, however, I have compared 25,000 mile oil used in a battery truck fleet of my customers, compared to fresh Shell Rotella T out of the bottle, and the 25,000 mile oil was still cleaner and stronger than the Shell Rotella out of the bottle.

What is the 25000 mile oil?

Bill, what you doing to the nordic this winter? See you soon.

Scott

If you had a pair of Merc Racing 850's - what would you run?

A good 20w50.

Ken

Rage,
The oil I was talking about had 25000 miles on it, without being changed. That is what I meant.